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Title: Dinosaurs - With Special Reference to the American Museum Collections
Author: Matthew, William Diller, 1871-1930
Language: English
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Copyright Status: Not copyrighted in the United States. If you live elsewhere check the laws of your country before downloading this ebook. See comments about copyright issues at end of book.

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DINOSAURS

With Special Reference to the American Museum Collections

by

W. D. MATTHEW

Curator of Vertebrate Palæontology



... '_Dragons of the prime
That tare each other in their slime_'


[Illustration: SKULL OF THE GREAT CARNIVOROUS DINOSAUR
TYRANNOSAURUS IN THE AMERICAN MUSEUM.]


New York
American Museum of Natural History
1915



DINOSAURS.

TABLE OF CONTENTS.


CHAPTER I.     The Age of Reptiles. Its Antiquity, Duration
               and Significance in Geological History.               9

CHAPTER II.    North America in the Age of Reptiles.
               Its Geographic and Climatic Changes.                 16

CHAPTER III.   Kinds of Dinosaurs. Common Characters and
               Differences between the various Groups.
               Classification.                                      25

CHAPTER IV.    The Carnivorous Dinosaurs--Allosaurus,
               Tyrannosaurus, Ornitholestes, etc.                   33

CHAPTER V.     The Amphibious Dinosaurs--Brontosaurus,
               Diplodocus, etc.                                     60

CHAPTER VI.    The Beaked Dinosaurs.
               The Iguanodonts--Iguanodon, Camptosaurus.            75

CHAPTER VII.   The Beaked Dinosaurs (continued). The
               Duckbilled Dinosaurs--Trachodon, Saurolophus.        82

CHAPTER VIII.  The Beaked Dinosaurs (continued). The
               Armored Dinosaurs--Stegosaurus, Ankylosaurus.       101

CHAPTER IX.    The Beaked Dinosaurs (concluded). The
               Horned Dinosaurs--Triceratops, etc.                 107

CHAPTER X.     Geographical Distribution of Dinosaurs.             114

CHAPTER XI.    Collecting Dinosaurs. How and Where they are
               Found. The First Discovery of Dinosaurs in
               the West. The Bone-Cabin Quarry. Fossil
               Hunting by Boat in Canada.                          116



PREFACE.


This volume is in large part a reprint of various popular descriptions
and notices in the American Museum Journal and elsewhere by Professor
Henry Fairfield Osborn, Mr. Barnum Brown, and the writer. There has
been a considerable demand for these articles which are now mostly out
of print. In reprinting it seemed best to combine and supplement them
so as to make a consecutive and intelligible account of the Dinosaur
collections in the Museum. The original notices are quoted verbatim;
for the remainder of the text the present writer is responsible.
Professor S.W. Williston of Chicago University has kindly contributed
a chapter--all too brief--describing the first discoveries of
dinosaurs in the Western formations that have since yielded so large a
harvest.

The photographs of American Museum specimens are by Mr. A.E. Anderson;
the field photographs by various Museum expeditions; the restorations
by Mr. Charles R. Knight. Most of these illustrations have been
published elsewhere by Professor Osborn, Mr. Brown and others. The
diagrams, figs. 1-9, 24, 25, 37 and 40, are my own.

                         W. D. M.



CHAPTER I.

THE AGE OF REPTILES.

ITS ANTIQUITY, DURATION AND SIGNIFICANCE IN GEOLOGIC HISTORY.


Palæontology deals with the History of Life. Its time is measured in
geologic epochs and periods, in millions of years instead of
centuries. Man, by this measure, is but a creature of yesterday--his
"forty centuries of civilization"[1] but a passing episode. It is by
no means easy for us to adjust our perspective to the immensely long
spaces of time involved in geological evolution. We are apt to think
of all these extinct animals merely as prehistoric--to imagine them
all living at the same time and contending with our cave-dwelling
ancestors for the mastery of the earth.

In order to understand the place of the Dinosaurs in world-history, we
must first get some idea of the length of geologic periods and the
immense space of time separating one extinct fauna from another.

_The Age of Man._ Prehistoric time, as it is commonly understood, is
the time when barbaric and savage tribes of men inhabited the world
but before civilization began, and earlier than the written records on
which history is based. This corresponds roughly to the Pleistocene
epoch of geology; it is included along with the much shorter time
during which civilization has existed, in the latest and shortest of
the geological periods, the Quaternary. It was the age of the mammoth
and the mastodon, the megatherium and Irish deer and of other
quadrupeds large and small which are now extinct; but most of its
animals were the same species as now exist. It was marked by the great
episode of the Ice Age, when considerable parts of the earth's surface
were buried under immense accumulations of ice, remnants of which are
still with us in the icy covering of Greenland and Antarctica.

_The Age of Mammals._ Before this period was a very much longer
one--at least thirty times as long--during which modern quadrupeds
were slowly evolving from small and primitive ancestors into their
present variety of form and size. This is the Tertiary Period or Age
of Mammals. Through this long period we can trace step by step the
successive stages through which the ancestors of horses, camels,
elephants, rhinoceroses, etc., were gradually converted into their
present form in adaptation to their various habits and environment.
And with them were slowly evolved various kinds of quadrupeds whose
descendants do not now exist, the Titanotheres, Elotheres, Oreodonts,
etc., extinct races which have not survived to our time. Man, as such,
had not yet come into existence, nor are we able to trace any direct
and complete line of ancestry among the fossil species known to us;
but his collateral ancestors were represented by the fossil species
of monkeys and lemurs of the Tertiary period.

  [Illustration: Fig. 1.--The Later Ages of Geologic Time.]

_The Age of Reptiles._ Preceding the Age of Mammals lies a long vista
of geologic periods of which the later ones are marked by the
dominance of Reptiles, and are grouped together as the Age of Reptiles
or Mesozoic Era. This was the reign of the Dinosaurs, and in it we are
introduced to a world of life so different from that of today that we
might well imagine ourselves upon another planet.

None of the ordinary quadrupeds with which we are familiar then
existed, nor any related to nor resembling them. But in their place
were reptiles large and small, carnivorous and herbivorous, walking,
swimming and even flying.

_Crocodiles, Turtles and Sea Reptiles._ The Crocodiles and Turtles of
the swamps were not so very different from their modern descendants;
there were also sea-crocodiles, sea-turtles, huge marine lizards
(Mosasaurs) with flippers instead of feet; and another group of great
marine reptiles (Plesiosaurs) somewhat like sea-turtles but with long
neck and toothed jaws and without any carapace. These various kinds of
sea-reptiles took the place of the great sea mammals of modern times
(which were evolved during the Age of Mammals); of whales and
dolphins, seals and walruses, and manatees.

_Pterodactyls._ The flying Reptiles or Pterosaurians, partly took the
place of birds, and most of them were of small size. Strange
bat-winged creatures, the wing membrane stretched on the enormously
elongated fourth finger, they are of all extinct reptiles the least
understood, the most difficult to reconstruct and visualize as they
were in life.

_Dinosaurs._ The land reptiles were chiefly Dinosaurs, a group which
flourished throughout the Age of Reptiles and became extinct at its
close. "Dinosaur" is a general term which covers as wide a variety in
size and appearance as "Quadruped" among modern animals. And the
Dinosaurs in the Age of Reptiles occupied about the same place in
nature as the larger quadrupeds do today. They have been called the
Giant Reptiles, for those we know most about were gigantic in size,
but there were also numerous smaller kinds, the smallest no larger
than a cat. All of them had short, compact bodies, long tails, and
long legs for a reptile, and instead of crawling, they walked or ran,
sometimes upon all fours, more generally upon the hind limbs, like
ostriches, the long tail balancing the weight of the body. Some modern
lizards run this way on occasion, especially if they are in a hurry.
But the bodies of lizards are too long and their limbs too small and
slender for this to be the usual mode of progress, as it seems to have
been among the Dinosaurs.

  ANIMALS OF THE AGE OF REPTILES.
    LAND REPTILES.
      DINOSAURS corresponding to the larger quadrupeds or land
        mammals of today.
      CROCODILES, LIZARDS AND TURTLES still surviving.
    SEA REPTILES.
      PLESIOSAURS  } corresponding to whales, dolphins, seals,
      ICHTHYOSAURS } etc., or sea-mammals of today.
      MOSASAURS    }
    FLYING REPTILES OR PTEROSAURS.
    BIRDS WITH TEETH (scarce and little known).
    PRIMITIVE MAMMALS of minute size (scarce and little known).
    FISHES and INVERTEBRATES many of them of extinct races, all
      more or less different from modern kinds.

Fishes, large and small, were common in the seas and rivers of the Age
of Reptiles but all of them were more or less different from modern
kinds, and many belonged to ancient races now rare or extinct.

The lower animals or Invertebrates were also different from those of
today, although some would not be very noticeably so at first glance.
Among molluscs, the Ammonites, related to the modern Pearly Nautilus,
are an example of a race very numerous and varied during all the
periods of the Reptilian Era, but disappearing at its close, leaving
only a few collateral descendants in the squids, cuttlefish and nautili
of the modern seas. The Brachiopods were another group of molluscs, or
rather molluscoids for they were not true molluscs, less abundant even
then than in previous ages and now surviving only in a few rare and
little known types such as the lamp-shell (_Terebratulina_).

_Insects._ The Insect life of the earlier part of the Age of Reptiles
was notable for the absence of all the higher groups and orders,
especially those adapted to feed on flowers. There were no butterflies
or moths, no bees or wasps or ants although there were plenty of
dragonflies, cockroaches, bugs and beetles. But in the latter part of
this era, all these higher orders appeared along with the flowering
plants and trees.

_Plants._ The vegetation in the early part of the era was very
different both from the gloomy forests of the more ancient Coal Era
and from that which prevails today. Cycads, ferns and fern-like
plants, coniferous trees, especially related to the modern
_Araucaria_ or Norfolk Island Pine, Ginkgos still surviving in China,
and huge equisetae or horsetail rushes, still surviving in South
American swamps and with dwarfed relatives throughout the world, were
the dominant plant types of that era. The flowering plants and
deciduous trees had not appeared. But in the latter half of the era
these appeared in ever increasing multitudes, displacing the lower
types and relegating them to a subordinate position. Unlike the more
rapidly changing higher animals these ancient Mesozoic groups of
plants have not wholly disappeared, but still survive, mostly in
tropical and southern regions or as a scanty remnant in contrast with
their once varied and dominant role.

There is every reason to believe that upon the appearance of these
higher plants whose flower and fruit afforded a more concentrated and
nourishing food, depended largely the evolution of the higher animal
life both vertebrate and insect, of the Cenozoic or modern era.

FOOTNOTES:

[Footnote 1: The records of Egypt and Chaldaea extend back at least
sixty centuries.]



CHAPTER II.

NORTH AMERICA IN THE AGE OF REPTILES.

ITS GEOGRAPHIC AND CLIMATIC CHANGES.


North America in the Age of Reptiles would have seemed almost as
strange to our eyes in its geography as in its animals and plants. The
present outlines of its coast, its mountains and valleys, its rivers
and lakes, have mostly arisen since that time. Even the more ancient
parts of the continent have been profoundly modified through the
incessant work of rain and rivers and of the waves, tending to wear
down the land surfaces, of volcanic outbursts building them up, and of
the more mysterious agencies which raise or depress vast stretches of
mountain chains or even the whole area of a continent, and which tend
on the whole so far as we can see, to restore or increase the relief
of the continents, as the action of the surface waters tends to bring
them down to or beneath the sea level.

_Alternate Overflow and Emergence of Continents._ In a broad way these
agencies of elevation and of erosion have caused in their age-long
struggle an alternation of periods of overflow and periods of
continental emergence during geologic time. During the periods of
overflow, great portions of the low-lying parts of the continents were
submerged, and formed extensive but comparatively shallow seas. The
mountains through long continued erosion were reduced to gentle and
uniform slopes of comparatively slight elevation. Their materials were
brought down by rivers to the sea-coast, and distributed as
sedimentary formations over the shallow interior seas or along the
margins of the continents. But this load of sediments, transferred
from the dry land to the ocean margins and shallow seas, disturbed the
balance of weight (isostasy) which normally keeps the continental
platforms above the level of the ocean basins (which as shown by
gravity measurement are underlain by materials of higher specific
gravity than the continents). In due course of time, when the strain
became sufficient, it was readjusted by earth movements of a slowness
proportioned to their vastness. These movements while tending upon the
whole to raise the continents to or sometimes beyond their former
relief, did not reverse the action of erosion agencies in detail, but
often produced new lines or areas of high elevation.

  [Illustration: Fig. 2.--North America in the Later Cretacic
  Period. Map outlines after Schuchert.]

_Geologic Periods._ A geologic period is the record of one of these
immense and long continued movements of alternate submergence and
elevation of the continents. It begins, therefore, and ends with a
time of emergence, and includes a long era of submergence.

These epochs of elevation are accompanied by the development of cold
climates at the poles, and elsewhere of arid conditions in the
interior of the continents. The epochs of submergence are accompanied
by a warm, humid climate, more or less uniform from the equator to the
poles.

The earth has very recently, in a geologic sense, passed through an
epoch of extreme continental elevation the maximum of which was marked
by the "Ice Age." The continents are still emerged for the most part
almost to the borders of the "continental shelf" which forms their
maximum limit. And in the icy covering of Greenland and Antarctica a
considerable portion still remains of the great ice-sheets which at
their maximum covered large parts of North America and Europe. We are
now at the beginning of a long period of slow erosion and subsidence
which, if this interpretation of the geologic record be correct, will
in the course of time reduce the mountains to plains and submerge
great parts of the lowlands beneath the ocean. As compensation for the
lesser extent of dry land we may look forward to a more genial and
favorable climate in the reduced areas that remain above water.

  [Illustration: Fig. 3.--Relative Length of Ages of Reptiles,
  Mammals and Man.]

_Length of Geologic Cycles._ But these vast cycles of geographic and
climatic change will take millions of years to accomplish their
course. The brief span of human life, or even the few centuries of
recorded civilization are far too short to show any perceptible change
in climate due to this cause. The utmost stretch of a man's life will
cover perhaps one-two hundred thousandth part of a geologic period.
The time elapsed since the dawn of civilization is less than a
three-thousandth part. Of the days and hours of this geologic year,
our historic records cover but two or three minutes, our individual
lives but a fraction of a second. We must not expect to find records
of its changing seasons in human history, still less to observe them
personally.

  [Illustration: Fig. 4.--Relative Length of Prehistoric and
  Historic Time.]

There are indeed minor cycles of climate within this great cycle. The
great Ice Age through which the earth has so recently passed was
marked by alternations of severity and mildness of climate, of advance
and recession of the glaciers, and within these smaller cycles are
minor alternations whose effect upon the course of human history has
been shown recently by Professor Huntington ("The Pulse of Asia"). But
the great cycles of the geologic periods are of a scope far too vast
for their changes to be perceptible to us except through their
influence upon the course of evolution.

_The Later Cycles of Geologic Time._ The Reptilian Era opens with a
period of extreme elevation, which rivalled that of the Glacial Epoch
and was similarly accompanied by extensive glaciation of which some
traces are preserved to our day in characteristic glacial boulders,
ice scratches, and till, imbedded or inter-stratified in the strata of
the Permian age. Between these two extremes of continental emergence,
the Permian and the Pleistocene, we can trace six cycles of alternate
submergence and elevation, as shown in the diagram (Fig. 5),
representing the proportion of North America which is known to have
been above water during the six geologic periods that intervene.

From this diagram it will appear that the six cycles or periods were
by no means equal in the amount of overflow or complete recovery of
the drowned lands. The Cretacic period was marked by a much more
extensive and long continued flooding; the great plains west of the
Mississippi were mostly under water from the Gulf of Mexico to the
Arctic Ocean. The earlier overflows were neither so extensive nor so
long continued. The great uplift of the close of the Cretacic regained
permanently the great central region and united East and West, and the
overflows of the Age of Mammals were mostly limited to the South
Atlantic and Gulf coasts.

_Sedimentary Formations._ During the epochs of greatest overflow great
marine formations were deposited over large areas of what is now dry
land. These were followed as the land rose to sea level by extensive
marsh and delta formations, and these in turn by scattered and
fragmentary dry land deposits spread by rivers over their flood
plains. In the marine formations are found the fossil remains of the
sea-animals of the period; in the coast and delta formations are the
remains of those which inhabited the marshes and forests of the coast
regions; while the animals of the dryland, of plains and upland, left
their remains in the river-plain formations.

  [Illustration: Fig. 5.--Geologic Cycles and the Land Area of North
  America (after Schuchert).]

These last, however, fragmentary and loose and overlying the rest,
were the first to be swept away by erosion during the periods of
elevation; and of such formations in the Age of Reptiles very little,
if anything, seems to have been preserved to our day. Consequently we
know very little about the upland animals of those times, if as seems
very probable, they were more or less different from the animals of
the coast-forests and swamps. The river-plain deposits of the Age of
Mammals on the other hand, are still quite extensive, especially those
of its later epochs, and afford a fairly complete record in some parts
of the continent of the upland fauna of those regions.

_Occurrence of Dinosaur Bones._ Dinosaur bones are found mostly in the
great delta formations, and since those were accumulated chiefly in
the early stages of great continental elevations, it follows that our
acquaintance with Dinosaurs is mostly limited to those living at
certain epochs during the Age of Reptiles. In point of fact so far as
explorations have yet gone in this country, the Dinosaur fauna of the
close of the Jurassic and beginning of the Comanchic and that of the
later Cretacic are the only ones we know much about. The immense
interval of time that preceded, and the no less vast stretch of time
that separated them, is represented in the record of Dinosaur history
by a multitude of tracks and a few imperfect skeletons assigned to the
close of the Triassic period, and by a few fragments from formations
which may be intermediate in age between the Jurassic-Comanchic and
the late Cretacic. Consequently we cannot expect to trace among the
Dinosaurs, the gradual evolution of different races, as we can do
among the quadrupeds of the Age of Mammals.

_Imperfection of the Geologic Record._ The Age of Mammals in North
America presents a moving picture of the successive stages in the
evolution of modern quadrupeds; the Age of Reptiles shows (broadly
considered) two photographs representing the land vertebrates of two
long distant periods, as remote in time from each other as the later
one is remote from the present day. Of the earlier stages in the
evolution of the Dinosaurs there are but a few imperfect sketches in
this country; in Europe the picture is more complete. In the course of
time, as exploration progresses, we shall no doubt recover more
complete records. But probably we shall never have so complete a
history of the terrestrial life of the Age of Reptiles as we have of
the Age of Mammals. The records are defective, a large part of them
destroyed or forever inaccessible.



CHAPTER III.

KINDS OF DINOSAURS.

COMMON CHARACTERS AND DIFFERENCES BETWEEN THE VARIOUS GROUPS.


In the preceding chapter we have attempted to point out the place in
nature that the Dinosaurs occupied and the conditions under which they
lived. They were the dominant land animals of their time, just as the
quadrupeds were during the Age of Mammals. Their sway endured for a
long era, estimated at nine millions of years, and about three times
as long as the period which has elapsed since their disappearance.
They survived vast changes in geography and climate, and became
extinct through a combination of causes not fully understood as yet;
probably the great changes in physical conditions at the end of the
Cretacic period, and the development of mammals and birds, more
intelligent, more active, and better adapted to the new conditions of
life, were the most important factors in their extinction.

The Dinosaurs originated, so far as we can judge, as lizard-like
reptiles with comparatively long limbs, long tails, five toes on each
foot, tipped with sharp claws, and with a complete series of sharp
pointed teeth. It would seem probable that these ancestors were more
or less bipedal, and adapted to live on dry land. They were probably
much like the modern lizards in size, appearance and habitat:[2]

From this ancestral type the Dinosaurs evolved into a great variety of
different kinds, many of them of gigantic size, some herbivorous, some
carnivorous; some bipedal, others quadrupedal; many of them protected
by various kinds of bony armor-plates, or provided with horns or
spines; some with sharp claws, others with blunted claws or hoofs.

  [Illustration: Fig. 6.--Outline Restorations of Dinosaurs. Scale
  about nineteen feet to the inch.]

These various kinds of Dinosaurs are customarily grouped as follows:

I. _Carnivorous Dinosaurs_ or _Theropoda_. With sharp pointed teeth,
sharp claws; bipedal, with bird-like hind feet, generally
three-toed;[3] the fore-limbs adapted for grasping or tearing, but not
for support of the body. The head is large, neck of moderate length,
body unarmored. The principal Dinosaurs of this group in America are

_Allosaurus_, _Ornitholestes_--Upper Jurassic period.

_Tyrannosaurus, Deinodon, Albertosaurus, Ornithomimus_--Upper Cretacic
period.

  [Illustration: Fig. 7.--Skulls of Dinosaurs, illustrating the
  principal types--_Anchisaurus_ after Marsh, the others from
  American Museum specimens.]

II. _Amphibious Dinosaurs_ or _Sauropoda_. With blunt-pointed teeth
and blunt claws, quadrupedal, with elephant-like limbs and feet, long
neck and small head. Unarmored. Principal dinosaurs of this group in
America are _Brontosaurus_, _Diplodocus_, _Camarasaurus_
(_Morosaurus_) and _Brachiosaurus_, all of the Upper Jurassic and
Comanchic periods.

III. _Beaked Dinosaurs_ or _Predentates_. With a horny beak on the
front of the jaw, cutting or grinding teeth behind it. All
herbivorous, with pelvis of peculiar type, with hoofs instead of
claws, and many genera heavily armored. Mostly three short toes on the
hind foot, four or five on the fore foot. This group comprises animals
of very different proportions as follows:

1. _Iguanodonts._ Bipedal, unarmored, with a single row of serrated
cutting teeth, three-toed hind feet. Upper Jurassic, Comanchic and
Cretacic. _Camptosaurus_ is the best known American genus.

2. _Trachodonts_ or _Duck-billed Dinosaurs_. Like the Iguanodonts but
with numerous rows of small teeth set close together to form a
grinding surface. Cretacic period. _Trachodon, Hadrosaurus,
Claosaurus, Saurolophus, Corythosaurus, etc._

3. _Stegosaurs_ or _Armored Dinosaurs_. Quadrupedal dinosaurs with
elephantine feet, short neck, small head, body and tail armored with
massive bony plates and often with large bony spines. Teeth in a
single row, like those of Iguanodonts. _Stegosaurus_ of the Upper
Jurassic, _Ankylosaurus_ of the Upper Cretacic.

  [Illustration: Fig. 8.--Hind Feet of Dinosaurs, to show the three
  chief types (Theropoda, Orthopoda, Sauropoda).]

4. _Ceratopsian_ or _Horned Dinosaurs_. Quadrupedal with elephantine
feet, short neck, very large head enlarged by an enormous bony frill
covering the neck, with a pair of horns over the eyes and a single
horn in front. Teeth in a single row, but broadened out and adapted
for grinding the food. No body armor. _Triceratops_ is the best known
type. _Monoclonius_, _Ceratops_, _Torosaurus_ and _Anchiceratops_ are
also of this group. All from the Cretacic period.

_Classification of Dinosaurs._ It is probable that the Dinosaurs are
not really a natural group or order of reptiles, although they have
been generally so considered. The Carnivorous and Amphibious Dinosaurs
in spite of their diverse appearance and habits, are rather nearly
related, while the Beaked Dinosaurs form a group apart, and may be
descendants of a different group of primitive reptiles. These
relations are most clearly seen in the construction of the pelvis (see
fig. 9). In the first two groups the pubis projects downward and
forward as it does in the majority of reptiles, and the ilium is a
high rounded plate; while in the others the pelvis is of a wholly
different type, strongly suggesting the pelvis of birds.

  [Illustration: Fig. 9.--Pelves of Dinosaurs illustrating the two
  chief types (Saurischia, Ornithischia) and their variations.]

Recent researches upon Triassic dinosaurs, especially by the
distinguished German savants, Friedrich von Huene, Otto Jaekel and the
late Eberhard Fraas, and the discovery of more complete specimens of
these animals, also clear up the true relationships of these
primitive dinosaurs which have mostly been referred hitherto to the
Theropoda or Megalosaurians. The following classification is somewhat
more conservative than the arrangement recently proposed by von Huene.

 ORDER SAURISCHIA Seeley.
   Suborder _Coelurosauria_ von Huene
       (=Compsognatha Huxley, Symphypoda Cope.)
     Fam. Podokesauridæ       Triassic, Connecticut.
      "   Hallopodidæ         Jurassic, Colorado.
      "   Coeluridæ           Jurassic and Comanchic, North America.
      "   Compsognathidæ      Jurassic, Europe.
   Suborder _Pachypodosauria_ von Huene.
     Fam. Anchisauridæ        Triassic, North America and Europe.
      "   Zanclodontidæ    }
      "   Plateosauridæ    }  Triassic, Europe.*
   Suborder _Theropoda_ Marsh (=Goniopoda Cope)
     Fam. Megalosauridæ       Jurassic and Comanchic.
      "   Deinodontidæ        Cretacic.
      "   Ornithomimidæ       Cretacic, North America.
   Suborder _Sauropoda_ Marsh
       (=Opisthocoelia Owen, Cetiosauria Seeley.)
     Fam. Cetiosauridæ     }
      "   Morosauridæ      }  Jurassic and Comanchic.
      "   Diplodocidæ      }
 Order ORNITHISCHIA Seeley
     (=Orthopoda Cope, Predentata Marsh.)
   Suborder _Ornithopoda_ Marsh (Iguanodontia Dollo)
     Fam. Nanosauridæ         Jurassic, Colorado.
      "   Camptosauridæ    }
      "   Iguanodontidæ    }  Jurassic and Comanchic.
      "   Trachodontidæ          (=Hadrosauridæ), Cretacic.
   Suborder _Stegosauria_ Marsh.
     Fam. Scelidosauridæ   }  Jurassic and Comanchic.
      "   Stegosauridæ     }
      "   Ankylosauridæ          (=Nodosauridæ), Cretacic.
   Suborder _Ceratopsia_ Marsh.
     Fam. Ceratopsidæ         Cretacic.

* Regarded by Dr. von Huene as ancestral respectively to the
  Theropoda and Sauropoda.

FOOTNOTES:

[Footnote 2: If some vast catastrophe should today blot out all the
mammalian races including man, and the birds, but leave the lizards
and other reptiles still surviving, with the lower animals and plants,
we might well expect the lizards in the course of geologic periods to
evolve into a great and varied land fauna like the Dinosaurs of the
Mesozoic Era.]

[Footnote 3: The ancestral types have four complete toes, but in the
true Theropoda the inner digit is reduced to a small incomplete
remnant, its claw reversed and projecting at the back of the foot, as
in birds.]



CHAPTER IV.

THE CARNIVOROUS DINOSAURS, ALLOSAURUS, TYRANNOSAURUS,
ORNITHOLESTES, ETC.

SUB-ORDER THEROPODA.


The sharp teeth, compressed and serrated like a palaeolithic spear
point, and the powerful sharp-pointed curved claws on the feet, prove
the carnivorous habits of these dinosaurs. The well-finished joints,
dense texture of the hollow bones and strongly marked muscle-scars
indicate that they were active and powerful beasts of prey. They range
from small slender animals up to the gigantic _Tyrannosaurus_
equalling the modern elephant in bulk. They were half lizard, half
bird in proportions, combining the head, the short neck and small fore
limbs and long snaky tail of the lizard with the short, compact body,
long powerful hind limbs and three-toed feet of the bird. The skin was
probably either naked or covered with horny scales as in lizards and
snakes; at all events it was not armor-plated as in the crocodile.[4]
They walked or ran upon the hind legs; in many of them the fore limbs
are quite unfitted for support of the body and must have been used
solely in fighting or tearing their prey.

  [Illustration: Fig. 10.--Hind Limb of Allosaurus, Dr. J.L. Wortman
  standing to one side. Dr. Wortman is one of the most notable and
  successful collectors of fossil vertebrates and was in charge of
  the Museum's field work in this department from 1891-1898.]

The huge size of some of these Mesozoic beasts of prey finds no
parallel among their modern analogues. It is only among marine animals
that we find predaceous types of such gigantic size. But among the
carnivorous dinosaurs we fail to find any indications of aquatic or
even amphibious habits. They might indeed wade in the water, but they
could hardly be at home in it, for they were clearly not good
swimmers. We must suppose that they were dry land animals or at most
swamp dwellers.

_Dinosaur Footprints._ The ancestors of the Theropoda appear first in
the Triassic period, already of large size, but less completely
bipedal than their successors. Incomplete skeletons have been found in
the Triassic formations of Germany[5] but in this country they are
chiefly known from the famous fossil footprints (or "bird-tracks" as
they were at first thought to be), found in the flagstone quarries at
Turner's Falls on the Connecticut River, in the vicinity of Boonton,
New Jersey, and elsewhere. These tracks are the footprints of numerous
kinds of dinosaurs, large and small, mostly of the carnivorous group,
which lived in that region in the earlier part of the Age of Reptiles,
and much has been learned from them as to the habits of the animals
that made them. The tracks ascribed to carnivorous dinosaurs run in
series with narrow tread, short or long steps, here and there a light
impression of tail or forefoot and occasionally the mark of the shank
and pelvis when the animal settled back and squatted down to rest a
moment. The modern crocodiles when they lift the body off the ground,
waddle forward with the short limbs wide apart, and even the lizards
which run on their hind legs have a rather wide tread. But these
dinosaurs ran like birds, setting one foot nearly in front of the
other, so that the prints of right and left feet are nearly in a
straight line. This was on account of their greater length of limb,
which made it easy for them to swing the foot directly underneath the
body at each step like mammals and birds, and thus maintain an even
balance, instead of wabbling from side to side as short legged animals
are compelled to do.

Of the animals that made these innumerable tracks the actual remains
found thus far in this country are exceedingly scanty. Two or three
incomplete skeletons of small kinds are in the Yale Museum, of which
_Anchisaurus_ is the best known.

_Megalosaurus._ Fragmentary remains of this huge carnivorous dinosaur
were found in England nearly a century ago, and the descriptions by
Dean Buckland and Sir Richard Owen and the restorations due to the
imaginative chisel of Waterhouse Hawkins, have made it familiar to
most English readers. Unfortunately it was, and still remains, very
imperfectly known. It was very closely related to the American
_Allosaurus_ and unquestionably similar in appearance and habits.[6]


ALLOSAURUS.

The following extract is from the American Museum Journal for January
1908.[7]

"Although smaller than its huge contemporary Brontosaurus, this animal
is of gigantic proportions being 34 feet 2 inches in length, and 8
feet 3 inches high."

  [Illustration: Fig. 11.--MOUNTED SKELETON OF ALLOSAURUS IN THE
  AMERICAN MUSEUM. _After Osborn_]

_History of the Allosaurus Skeleton._ "This rare and finely preserved
skeleton was collected by Mr. F.F. Hubbell in October 1879, in the
Como Bluffs near Medicine Bow, Wyoming, the richest locality in
America for dinosaur skeletons, and is a part of the great collection
of fossil reptiles, amphibians and fishes gathered together by the
late Professor E.D. Cope, and presented to the American Museum in 1899
by President Jesup.

"Shortly after the Centennial Exposition (1876) it had been planned
that Professor Cope's collection of fossils should form part of a
great public museum in Fairmount Park, Philadelphia, the city
undertaking the cost of preparing and exhibiting the specimens, an
arrangement similar to that existing between the American Museum and
the City of New York.[8]

"The plan, however, fell through, and the greater part of this
magnificent collection remained in storage in the basement of Memorial
Hall in Fairmount Park, for the next twenty years. From time to time
Professor Cope removed parts of the collection to his private museum
in Pine Street, for purposes of study and scientific description. He
seems, however, to have had no idea of the perfection and value of
this specimen. In 1899 when the collection was purchased from his
executors by Mr. Jesup, the writer went to Philadelphia under the
instructions of Professor Osborn, Curator of Fossil Vertebrates, to
superintend the packing and removal to the American Museum. At that
time the collection made by Hubbell was still in Memorial Hall, and
the boxes were piled up just as they came in from the West, never
having been unpacked. Professor Cope's assistant, Mr. Geismar,
informed the writer that Hubbell's collection was mostly fragmentary
and not of any great value. Mr. Hubbell's letters from the field
unfortunately were not preserved, but it is likely that they did not
make clear what a splendid find he had made, and as some of his
earlier collections had been fragmentary and of no great interest, the
rest were supposed to be of the same kind.

"When the Cope Collection was unpacked at the American Museum, this
lot of boxes, not thought likely to be of much interest, was left
until the last, and not taken in hand until 1902 or 1903. But when
this specimen was laid out, it appeared that a treasure had come to
light. Although collected by the crude methods of early days, it
consisted of the greater part of the skeleton of a single individual,
with the bones in wonderfully fine preservation, considering that they
had been buried for say eight million years. They were dense black,
hard and uncrushed, even better preserved and somewhat more complete
than the two fine skeletons of Allosaurus from Bone-Cabin Quarry, the
greatest treasures that this famous quarry had supplied. The great
carnivorous dinosaurs are much rarer than the herbivorous kinds, and
these three skeletons are the most complete that have ever been found.
In all the years of energetic exploration that the late Professor
Marsh devoted to searching for dinosaurs in the Jurassic and
Cretaceous formations of the West, he did not obtain any skeletons of
carnivorous kinds anywhere near as complete as these, and their
anatomy was in many respects unknown or conjectural. By comparison of
the three Allosaurus skeletons with one another and with other
specimens of carnivorous dinosaurs of smaller size in this and other
museums, particularly in the National Museum and the Kansas University
Museum, we have been able to reconstruct the missing parts of the Cope
specimen with very little possibility of serious error."

_Evidence for Combining and Posing this Mount._ "An incomplete
specimen of Brontosaurus, found by Doctor Wortman and Professor W.C.
Knight of the American Museum Expedition of 1897, had furnished
interesting data as to the food and habits of Allosaurus, which were
confirmed by several other fragmentary specimens obtained later in the
Bone-Cabin Quarry. In this Brontosaurus skeleton several of the bones,
especially the spines of the tail vertebrae, when found in the rock,
looked as if they had been scored and bitten off, as though by some
carnivorous animal which had either attacked the Brontosaurus when
alive, or had feasted upon the carcass. When the Allosaurus jaw was
compared with these score marks, it was found to fit them exactly, the
spacing of the scratches being the same as the spacing of the teeth.
Moreover, on taking out the Brontosaurus vertebrae from the quarry, a
number of broken off teeth of Allosaurus were found lying beside them.
As no other remains of Allosaurus or any other animal were
intermingled with the Brontosaurus skeleton, the most obvious
explanation was that these teeth were broken off by an Allosaurus
while devouring the Brontosaurus carcass. Many of the bones of other
herbivorous dinosaurs found in the Bone-Cabin Quarry were similarly
scored and bitten off, and the teeth of Allosaurus were also found
close to them.

"With these data at hand the original idea was conceived of combining
these two skeletons, both from the same formation and found within a
few miles of each other, to represent what must actually have happened
to them in the remote Jurassic period, and mount the Allosaurus
skeleton standing over the remains of a Brontosaurus in the attitude
of feeding upon its carcass. Some modifications were made in the
position to suit the exigencies of an open mount, and to accommodate
the pose to the particular action; the head of the animal was lifted a
little, one hind foot planted upon the carcass, while the other,
resting upon the ground bears most of the weight. The fore feet, used
in these animals only for fighting or for tearing their prey, not for
support, are given characteristic attitudes, and the whole pose
represents the Allosaurus devouring the carcass and raising head and
fore foot in a threatening manner as though to drive away intruders.
The balance of the various parts was carefully studied and adjusted
under direction of the curator. The preparation and mounting of the
specimen were done by Mr. Adam Hermann, head preparator, and his
assistants, especially Messrs. Falkenbach and Lang.

  [Illustration: Fig. 12.--Restoration of Allosaurus by C.R. Knight.
  _After Osborn_]

"As now exhibited in the Dinosaur Hall, this group gives to the
imaginative observer a most vivid picture of a characteristic scene in
that bygone age, millions of years ago, when reptiles were the lords
of creation, and 'Nature, red in tooth and claw' had lost none of her
primitive savagery, and the era of brute force and ferocity showed
little sign of the gradual amelioration which was to come to pass in
future ages through the predominance of superior intelligence."

_Appearance and Habits of Allosaurus._ A study of the mechanism of the
Allosaurus skeleton shows us in the first place that the animal is
balanced on the hind limbs, the long heavy tail making an adequate
counterpoise for the short compact body and head. The hind limbs are
nine feet in length when extended, about equal to the length of the
body and neck, and the bones are massively proportioned. When the
thigh bone is set in its normal position, as indicated by the position
of the scars and processes for attachment of the principal muscles
(see under Brontosaurus for the method used to determine this), the
knee bends forward as in mammals and birds, not outward as in most
modern reptiles. The articulations of the foot bones show that the
animal rested upon the ends of the metapodials, as birds and many
mammals do, not upon the sole of the foot like crocodiles or lizards.
The flat vertebral joints show that the short compact body was not as
flexible as the longer body of crocodiles or lizards, in which the
articulations are of the ball and socket type showing that in them
this region was very flexible. The tail also shows a limited
flexibility. It could not be curled or thrown over the back, but
projected out behind the animal, swinging from side to side or up and
down as much as was needed for balance. The curvature of the ribs
shows that the body was narrow and deep, unlike the broad flattened
body of the crocodile or the less flattened but still broad body of
the lizard. The loose hung jaw, articulated far back, shows by the set
of its muscles that it was capable of an enormous gape; while in the
skull there is evidence of a limited movement of the upper jaw on the
cranial portion, intended probably to assist in the swallowing of
large objects, like the double jointed jaw of a snake.

As to the nature of the skin we have no exact knowledge. We may be
sure that it had no bony armor like the crocodile, for remains of any
such armor could not fail to be preserved with the skeletons, as it
always is in fossil crocodiles or turtles. Perhaps it was scaly like
the skin of lizards and snakes, for the horny scales of the body are
not preserved in fossil skeletons of these reptiles. But if so we
might expect from the analogy of the lizard that the scales of the
head would be ossified and preserved in the fossil; and there is
nothing of this kind in the Carnivorous Dinosaurs. We can exclude
feathers from consideration, for these dinosaurs have no affinities to
birds, and there is no evidence for feathers in any dinosaur. Probably
the best evidence is that of the Trachodon or duck-billed dinosaur
although this animal was but distantly related to the Allosaurus. In
Trachodon (see p. 94), we know that the skin bore neither feathers nor
overlapping scales but had a curiously patterned mosaic of tiny
polygonal plates and was thin and quite flexible. Some such type of
skin as this, in default of better evidence, we may ascribe to the
Allosaurus.

  [Illustration: Fig. 13.--View in the Hell Creek badlands in
  central Montana, where the Tyrannosaurus skeleton was found.]

As to its probable habits, it is safe to infer (see p. 33), that it
was predaceous, active and powerful, and adapted to terrestrial life.
Its methods of attack and combat must have been more like those of
modern reptiles than the more intelligent methods of the mammalian
carnivore. The brain cast of Allosaurus indicates a brain of similar
type and somewhat inferior grade to that of the modern crocodile or
lizard, and far below the bird or mammal in intelligence. The keen
sense of smell of the mammal, the keen vision of the bird, the highly
developed reasoning power of both, were absent in the dinosaur as in
the lizard or crocodile. We may imagine the Allosaurus lying in wait,
watching his prey until its near approach stimulates him into a
semi-instinctive activity; then a sudden swift rush, a fierce snap of
the huge jaws and a savage attack with teeth and claws until the
victim is torn in pieces or swallowed whole. But the stealthy,
persistent tracking of the cat or weasel tribe, the intelligent
generalship of the wolf pack, the well planned attack at the most
vulnerable point in the prey, characteristic of all the predaceous
mammals, would be quite impossible to the dinosaur. By watching the
habits of modern reptiles we may gain a much better idea of his
capacities and limitations than if we judge only from the efficiency
of his teeth and claws, and forget the inferior intelligence that
animated these terrible weapons.


TYRANNOSAURUS.

The "Tyrant Saurian" as Professor Osborn has named him, was the climax
of evolution of the giant flesh-eating dinosaurs. It reached a length
of forty-seven feet, and in bulk must have equalled the mammoth or the
mastodon or the largest living elephants. The massive hind limbs,
supporting the whole weight of the body, exceeded the limbs of the
great proboscideans in bulk, and in a standing position the animal was
eighteen to twenty feet high, as against twelve for the largest
African elephants or the southern mammoth. The head (see frontispiece)
is 4 feet 3 inches long, 3 ft. 4 inches deep, and 2 ft. 9 inches wide;
the long deep powerful jaws set with teeth from 3 to 6 inches long and
an inch wide. To this powerful armament was added the great sharp
claws of the hind feet, and probably the fore feet, curved like those
of eagles, but six or eight inches in length.

During ten years explorations in the Western Cretaceous formations,
Mr. Brown has secured for the Museum three skeletons of this
magnificent dinosaur, incomplete, but finely preserved. The first,
found in 1900, included the jaws, a large part of backbone and ribs,
and some limb bones. The second included most of skull and jaws,
backbone, ribs and pelvis and the hind limbs and feet, but not tail.
The third consisted of a perfect skull and jaws, the backbone, ribs,
pelvis and nearly all of the tail, but no limbs. From these three
specimens it has been possible to reconstruct the entire skeleton. The
exact construction of the fore feet is the only doubtful part. The
fore-limb is very small relatively to the huge size of the animal, but
probably was constructed much as in the _Allosaurus_ with two or three
large curved claws, the inner claw opposing the others.

  [Illustration: Fig. 14.--Quarry from which the _Tyrannosaurus_
  skeleton was taken. American Museum camp in foreground.]

The missing parts of the two best skeletons have been restored, and
with the help of two small models of the skeleton, a group has been
made ready for mounting as the central piece of the proposed
Cretaceous Dinosaur Hall. One of the skeletons is temporarily placed
in the centre of the Quaternary Hall, space for it in the present
Dinosaur Hall being lacking. Following is Professor Osborn's
description of the preparation of this group:[9]

"The mounting of these two skeletons presents mechanical problems of
very great difficulty. The size and weight of the various parts are
enormous. The height of the head in the standing position reaches from
18 to 20 feet above the ground; the knee joint alone reaches 6 feet
above the ground. All the bones are massive; the pelvis, femur and
skull are extremely heavy. Experience with _Brontosaurus_ and with
other large dinosaurs proves that it is impossible to design a
metallic frame in the right pose in advance of assembling the parts.
Even a scale restoration model of the animal as a whole does not
obviate the difficulty.

"Accordingly in preparing to mount _Tyrannosaurus_ for exhibition a
new method has been adopted, namely, to _prepare a scale model of
every bone in the skeleton_ and mount this small skeleton with
flexible joints and parts so that all studies and experiments as to
pose can be made with the models.

"This difficult and delicate undertaking was entrusted to Mr. Erwin
Christman of the artistic staff of the Department of Vertebrate
Palaeontology of the Museum, who has prepared two very exact models to
a one-sixth scale, representing our two skeletons of _Tyrannosaurus
rex_, which fortunately are of exactly the same size. A series of
three experiments by Mr. Christman on the pose of _Tyrannosaurus_,
under the direction of the author and Curator Matthew, were not
satisfactory. The advice of Mr. Raymond L. Ditmars, Curator of
Reptiles in the New York Zoological Park, was sought and we thus
obtained the fourth pose, which is shown in the photographs published
herewith.

  [Illustration: Fig. 15.--Model of _Tyrannosaurus_ group for the
  Cretaceous Dinosaur Hall.]

"The fourth pose or study, for the proposed full sized mount, is that
of two reptiles of the same size attracted to the same prey. One
reptile is crouching over its prey (which is represented by a portion
of a skeleton). The object of this depressed pose is to bring the
perfectly preserved skull and pelvis very near the ground within easy
reach of the visiting observer. The second reptile is advancing, and
attains very nearly the full height of the animal. The general effect
of this group is the best that can be had and is very realistic,
particularly the crouching figure. A fifth study will embody some
further changes. The upright figure is not well balanced and will be
more effective with the feet closer together, the legs straighter and
the body more erect. These reptiles have a series of strong abdominal
ribs not shown in the models. The fourth position places the pelvis in
an almost impossible position as will be noted from the ischium and
pubis.

"The lateral view of this fourth pose represents the animals just
prior to the convulsive single spring and tooth grip which
distinguishes the combat of reptiles from that of all mammals,
according to Mr. Ditmars.

"The rear view of the standing skeleton displays the peculiarly avian
structure of the iliac junction with the sacral plate, characteristic
of these very highly specialized dinosaurs, also the marked reduction
of the upper end of the median metatarsal bone, which formerly was
believed to be peculiar to _Ornithomimus_."

This model of the group is on exhibition with the mounted skeleton.

As compared with its predecessor _Allosaurus_, the _Tyrannosaurus_ is
much more massively proportioned throughout. The skull is more solid,
the jaws much deeper and more powerful, the fore limb much smaller,
the tail shorter, the hind limb straighter and the foot bones more
compacted so that the animal was more strictly "digitigrade,"
approaching the ostriches more closely in this particular.

  [Illustration: Fig. 16.--SKELETON OF TYRANNOSAURUS IN COMPARISON
  WITH HUMAN SKELETON.]

This animal probably reached the maximum of size and of development of
teeth and claws of which its type of animal mechanism was capable. Its
bulk precluded quickness and agility. It must have been designed to
attack and prey upon the ponderous and slow moving Horned and Armored
Dinosaurs with which its remains are found, and whose massive cuirass
and weapons of defense are well matched with its teeth and claws. The
momentum of its huge body involved a seemingly slow and lumbering
action, an inertia of its movements, difficult to start and difficult
to shift or to stop. Such movements are widely different from the
agile swiftness which we naturally associate with a beast of prey. But
an animal which exceeds an average elephant in bulk, no matter what
its habits, is compelled by the laws of mechanics to the ponderous
movements appropriate to its gigantic size. These movements, directed
and controlled by a reptilian brain, must needs be largely automatic
and instinctive. We cannot doubt indeed that the Carnivorous Dinosaurs
developed, along with their elaborately perfected mechanism for
attack, an equally elaborate series of instincts guiding their action
to effective purpose; and a complex series of automatic responses to
the stimulus afforded by the sight and action of their prey might
very well mimic intelligent pursuit and attack, always with certain
limits set by the inflexible character of such automatic adjustments.
But no animal as large as _Tyrannosaurus_ could leap or spring upon
another, and its slow stride quickening into a swift resistless rush,
might well end in unavoidable impalement upon the great horns of
_Triceratops_, futile weapons against a small and active enemy, but
designed no doubt to meet just such attacks as these. A true picture
of these combats of titans of the ancient world we cannot draw;
perhaps we will never be able to reconstruct it. But the above
considerations may serve to show how widely it would differ from the
pictures based upon any modern analogies.

One may well inquire why it is that no such gigantic carnivora have
evolved among the mammalian land animals. The largest predaceous
quadrupeds living today are the lion and tiger. The bears although
some of them are much larger, are not generally carnivorous, except
for the polar bear, which is partly aquatic, preying chiefly upon
seals and fish. There are indeed carnivorous whales of gigantic size,
but no very large land carnivore. There were, it is true, during the
Tertiary and Pleistocene, lions and other carnivores considerably
larger than the living species. But none of them attained the size of
their largest herbivorous contemporaries, or even approached it. Among
the dinosaurs on the other hand we find that--setting aside
Brontosaurus and its allies as aquatic--the predaceous kinds equalled
or exceeded the largest of the herbivorous sorts. The difference is
striking, and it does not seem likely that it is merely accidental.

The explanation lies probably in the fact that the large herbivorous
mammals are much more intelligent and active, and would be able to use
their weapons of defense so as to defy the attacks of relatively slow
moving giant beasts of prey, as they do also the more active but less
powerful assaults of smaller ones. The elephant or the rhinoceros is
in fact practically immune from the attacks of carnivora, and would
still be so were the carnivora to increase in size. The large modern
carnivora prey upon herbivores of medium or smaller size, which they
are active enough to surprise or run down. Carnivora of much larger
size would be too slow and heavy in movements to catch small prey,
while the larger herbivores by intelligent use of their defensive
weapons could still fend them off successfully. In consequence giant
carnivores would find no field for action in the Cenozoic world, and
hence they have not been evolved.

But the giant herbivorous dinosaurs, well armed or well defended
though they were, had not the intelligence to use those weapons
effectively under all circumstances. Thus they might be successfully
attacked, at least sometimes, by the powerful although slow moving
Megalosaurians.

The suggestion has also been made that these giant carnivores were
carrion-eaters rather than truly predaceous. The hypothesis can hardly
be effectively supported nor attacked. It is presented as a possible
alternate.

_Albertosaurus._ Closely allied to the _Tyrannosaurus_ but smaller,
about equal in size to _Allosaurus_, was the _Albertosaurus_ of the
Edmonton formation in Canada. It is somewhat older than the Tyrannosaur
although still of the late Cretacic period, and may have been ancestral
to it. A fine series of limbs and feet as also skull, tail, etc., are
in the Museum's collections. At or about this time carnivorous
dinosaurs of slightly smaller size are known to have inhabited New
Jersey; a fragmentary skeleton of one secured by Professor Cope in 1869
was described as _Laelaps_ (=_Dryptosaurus_).[10]

_Ornitholestes._ In contrast with the _Allosaurus_ and _Tyrannosaurus_
this skeleton represents the smaller and more agile carnivorous
dinosaurs which preyed upon the lesser herbivorous reptiles of the
period. These little dinosaurs were probably common during all the Age
of Reptiles, much as the smaller quadrupeds are today, but skulls or
skeletons are rarely found in the formations known to us. The
_Anchisaurus_, _Podokesaurus_ and other genera of the Triassic Period
have left innumerable tracks upon the sandy shales of the Newark
formation, but only two or three skeletons are known. A cast of one
of them is exhibited here. The original is preserved in the Yale
Museum. In the succeeding Jurassic Period we have the _Compsognathus_,
smallest of known dinosaurs, and this _Ornitholestes_ some six feet
long. A cast of the _Compsognathus_ skeleton is shown, the original
found in the lithographic limestone of Solenhofen is preserved in the
Munich Museum. The _Ornitholestes_ is from the Bone-Cabin Quarry in
Wyoming. The forefoot with its long slender digits is supposed to have
been adapted for grasping an active and elusive prey, and the name
(_Ornitho-lestes_ = bird-robber) indicates that that prey may
sometimes have been the primitive birds which were its contemporaries.
In the Cretacic Period, there were also small and medium sized
carnivorous dinosaurs, contemporary with the gigantic kinds; a
complete skeleton of _Ornithomimus_ at the entrance to the Dinosaur
Hall finely illustrates this group. In appearance most of these small
dinosaurs must have suggested long-legged bipedal lizards, running and
walking on their hind limbs, with the long tail stretched out behind
to balance the body. From what we know of their tracks it seems that
they walked or ran with a narrow treadway, the footsteps almost in the
middle line of progress. They did not hop like perching birds, nor did
they waddle like most living reptiles. Occasionally the tail or fore
feet touched the ground as they walked; and when they sat down, they
rested on the end of the pubic bones and on the tail. So much we can
infer from the footprint impressions. The general appearance is shown
in the restorations of _Ornitholestes_, _Compsognathus_ and
_Anchisaurus_ by Charles Knight.

  [Illustration: Fig. 17.--Skeleton of _Ornitholestes_ a small
  carnivorous dinosaur of the Jurassic period. American Museum No.
  619.]

  [Illustration: Fig. 18.--Restoration of _Ornitholestes_, by C.R.
  Knight under direction of Professor Osborn. _After Osborn_]

_Ornithomimus._ The skeleton of this animal from the Cretacic of
Alberta was found by the Museum expedition of 1914. It is
exceptionally complete, and has been mounted as a panel, in position
as it lay in the rock, and with considerable parts of the original
sandstone matrix still adherent. The long slender limbs, long neck,
small head and toothless jaws are all singularly bird-like, and afford
a striking contrast to the Tyrannosaurus. At the time of writing, its
adaptation and relationships have not yet been thoroughly
investigated.

  [Illustration: Fig. 19.--MOUNTED SKELETON OF BRONTOSAURUS IN THE
  AMERICAN MUSEUM.]

FOOTNOTES:

[Footnote 4: This is still doubtful in _Tyrannosaurus_. A number of
very curious plates were found with one specimen in a quarry. B.
Brown, 1913.]

[Footnote 5: Quite recently a series of more or less complete
skeletons have been secured from the upper Triassic (Keuper) near
Halberstadt in Germany. They are not true Megalosaurians, but
primitive types (Pachypodosauria) ancestral to both these and the
Sauropoda. Probably many of the Connecticut footprints were made by
animals of this primitive group. _Anchisaurus_ certainly belongs to
it.]

[Footnote 6: It is evidently "the dinosaur" of Sir Conan Doyle's "Lost
World" but the vivid description which the great English novelist
gives of its appearance and habits, based probably upon the Hawkins
restoration, is not at all in accord with inferences from what is now
known of these animals. See p. 44.]

[Footnote 7: Allosaurus, a carnivorous Dinosaur, and its Prey. By W.D.
Matthew. Am. Mus. Nat. Hist. Jour. Vol. viii, pp. 3-5, pl. 1.]

[Footnote 8: The cost of preparation is now defrayed by the Museum.]

[Footnote 9: Tyrannosaurus, Restoration and Model of the Skeleton. By
Henry Fairfield Osborn. Bull. Amer. Mus. Nat. Hist., 1913, vol. xxxii,
art. iv, pp. 91-92.]

[Footnote 10: Since these lines were written the Museum has secured
finely preserved skeletons of two or more kinds of Carnivorous
Dinosaurs from the Belly River formation in Canada.]



CHAPTER V.

THE AMPHIBIOUS DINOSAURS, BRONTOSAURUS, DIPLODOCUS, ETC.

SUB-ORDER OPISTHOCOELIA (CETIOSAURIA OR SAUROPODA).


These were the Giant Reptiles par-excellence, for all of them were of
enormous size, and some were by far the largest of all four-footed
animals, exceeded in bulk only by the modern whales. In contrast to
the carnivorous dinosaurs these are quadrupedal, with very small head,
blunt teeth, long giraffe-like neck, elephantine body and limbs, long
massive tail prolonged at the tip into a whip-lash as in the lizards.
Like the elephant they have five short toes on each foot, probably
buried in life in a large soft pad, but the inner digits bear large
claws, blunt like those of turtles, one in the fore foot, three in the
hind foot.

To this group belong the Brontosaurus and Diplodocus, the
Camarasaurus, Morosaurus and other less known kinds. All of them lived
during the late Jurassic and Comanchic ("Lower Cretaceous") and belong
to the older of the two principal Dinosaur faunas. They were
contemporaries of the Allosaurus and Megalosaurus, the Stegosaurus and
Iguanodon, but unlike the Carnivorous and Beaked Dinosaurs they
became wholly extinct before the Upper or true Cretacic, and left no
relatives to take part in the final epoch of expansion and prosperity
of the dinosaurian race at the close of the Reptilian era.

  [Illustration: Fig. 20.--Skeletons of _Brontosaurus_ (above) and
  _Diplodocus_ (below) in the American Museum. The parts preserved
  in these specimens are shaded. Scale, 10 feet=1 inch.]


BRONTOSAURUS.

The following description of the Brontosaurus skeleton in the American
Museum was first published in the American Museum Journal of April,
1905:[11]

"The Brontosaurus skeleton, the principal feature of the hall, is
sixty-six feet eight inches long. (The weight of the animal when alive
is estimated by W.K. Gregory at 38 tons). About one-third of the
skeleton including the skull is restored in plaster modelled or cast
from other incomplete skeletons. The remaining two-thirds belong to
one individual, except for a part of the tail, one shoulder-blade and
one hind limb, supplied from another skeleton of the same species.

"The skeleton was discovered by Mr. Walter Granger of the Museum
expedition of 1898, about nine miles north of Medicine Bow, Wyoming.
It took the whole of the succeeding summer to extract it from the
rock, pack it, and ship it to the Museum. Nearly two years were
consumed in removing the matrix, piecing together and cementing the
brittle and shattered petrified bone, strengthening it so that it
would bear handling, and restoring the missing parts of the bones in
tinted plaster. The articulation and mounting of the skeleton and
modelling of the missing bones took an even longer time, so that it
was not until February, 1905, that the Brontosaurus was at last ready
for exhibition.

  [Illustration: Fig. 21.--Excavating the _Brontosaurus_ skeleton.
  The upper photograph shows the anterior ribs of one side still
  lying in position. The backbone is being prepared for removal, the
  sections each containing three vertebrae, partly cased in plaster
  and burlap (see chapter XI.) The lower photograph shows a later
  stage of progress, the blocks being undercut and nearly ready to
  turn over and incase the under side. Strips of wood have been
  pasted into each section to strengthen it.]

"It will appear, therefore, that the collection, preparation and
mounting of this gigantic fossil has been a task of extraordinary
difficulty. No museum has ever before attempted to mount so large a
fossil skeleton, and the great weight and fragile character of the
bones made it necessary to devise especial methods to give each bone a
rigid and complete support as otherwise it would soon break in pieces
from its own weight. The proper articulating of the bones and posing
of the limbs were equally difficult problems, for the Amphibious
Dinosaurs, to which this animal belongs, disappeared from the earth
long before the dawn of the Age of Mammals, and their nearest
relatives, the living lizards, crocodiles, etc., are so remote from
them in either proportions or habits that they are unsatisfactory
guides in determining how the bones were articulated and are of but
little use in posing the limbs and other parts of the body in
positions that they must have taken during life. Nor among the higher
animals of modern times is there one which has any analogy in
appearance or habits of life to those which we have been obliged by
the study of the skeleton to ascribe to the Brontosaurus.

"As far as the backbone and ribs were concerned, the articulating
surfaces of the bones were a sufficient guide to enable us to pose
this part of the skeleton properly. The limb joints, however, are so
imperfect that we could not in this way make sure of having the bones
in a correct position. The following method, therefore, was adopted.

"A dissection and thorough study was made by the writer, with the
assistance of Mr. Granger, of the limbs of alligators and other
reptiles, and the position, size and action of the principal muscles
were carefully worked out. Then the corresponding bones of the
Brontosaurus were studied, and the position and size of the
corresponding muscles were worked out, so far as they could be
recognized from the scars and processes preserved on the bone. The
Brontosaurus limbs were then provisionally articulated and posed, and
the position and size of each muscle were represented by a broad strip
of paper extending from its origin to its insertion. The action and
play of the muscles on the limb of the Brontosaurus could then be
studied, and the bones adjusted until a proper and mechanically
correct pose was reached. The limbs were then permanently mounted in
these poses, and the skeleton as it stands is believed to represent,
as nearly as study of the fossil enables us to know, a characteristic
position that the animal actually assumed during life....

"In proportions and appearance the Brontosaurus was quite unlike any
living animal. It had a long thick tail like the lizards and
crocodiles, a long, flexible neck like an ostrich, a thick short,
slab-sided body and straight, massive, post-like limbs suggesting the
elephant, and a remarkably small head for the size of the beast. The
ribs, limb-bones and tail-bones are exceptionally solid and heavy; the
vertebrae of the back and neck, and the skull, on the contrary are
constructed so as to combine the minimum of weight with the large
surface necessary for the attachment of the huge muscles, the largest
possible articulating surfaces, and the necessary strength at all
points of strain. For this purpose they are constructed with an
elaborate system of braces and buttresses of thin bony plates
connecting the broad articulating surfaces and muscular attachments,
all the bone between these thin plates being hollowed into a
complicated system of air-cavities. This remarkable structure can be
best seen in the unmounted skeleton of _Camarasaurus_, another
Amphibious Dinosaur." (The scientific name _Camarasaurus_=chambered
lizard, has reference to this peculiarity of construction.)

"The teeth of the Brontosaurus indicate that it was an herbivorous
animal, feeding on soft vegetable food. Three opinions as to the
habitat of Amphibious Dinosaurs have been held by scientific
authorities. The first, advocated by Professor Owen, who described the
first specimens found sixty years ago (1841-60) and supported
especially by Professor Cope, has been most generally adopted. This
regards the animals as spending their lives entirely in shallow water,
partly immersed, wading about on the bottom, or perhaps occasionally
swimming, but unable to emerge entirely upon dry land.[12] More
recently, Professor Osborn has advocated the view that they resorted
occasionally to the land for egg laying or other purposes, and still
more recently the view has been taken by Mr. Riggs and the late
Professor Hatcher that they were chiefly terrestrial animals. The
writer inclines to the view of Owen and Cope, whose unequalled
knowledge of comparative anatomy renders their opinion on this
doubtful question especially authoritative.

  [Illustration: Fig. 22.--RESTORATION OF BRONTOSAURUS BY C.R.
  KNIGHT, UNDER DIRECTION OF PROFESSOR OSBORN. _After Osborn_]

"The contrast between the massive structure of the limb-bones, ribs
and tail, and the light construction of the backbone, neck and skull,
suggests that the animal was amphibious, living chiefly in shallow
water, where it could wade about on the bottom, feeding upon the
abundant vegetation of the coastal swamps and marshes, and pretty much
out of reach of the powerful and active Carnivorous Dinosaurs which
were its principal enemies. The water would buoy up the massive body
and prevent its weight from pressing too heavily on the imperfect
joints of the limb and foot bones, which were covered during life with
thick cartilage, like the joints of whales, sea-lizards and other
aquatic animals. If the full weight of the animal came on these
imperfect joints the cartilage would yield and the ends of the bones
would grind against each other, thus preventing the limb from moving
without tearing the joint to pieces. The massive, solid limb and foot
bones weighted the limbs while immersed in water, and served the same
purpose as the lead in a diver's shoes, enabling the Brontosaurus to
walk about firmly and securely under water. On the other hand, the
joints of the neck and back are exceptionally broad, well fitting and
covered with a much thinner surface of cartilage. The pressure was
thus much better distributed over the joint, and the full weight of
the part of the animal above water (reduced as it was by the cellular
construction of the bones) might be borne on these joints without the
cartilage giving way.

"Looking at the mounted skeleton we may see that if a line be drawn
from the hip joint to the shoulder-blade, all the bones below this are
massive, all above (including neck and head) are lightly constructed.
This line may be taken to indicate the average water-line, so to
speak, of this Leviathan of the Shallows. The long neck would enable
the animal, however, to wade to a considerable depth, and it might
forage for food either in the branches or the tops of trees, or more
probably, among the soft succulent water-plants of the bottom. The row
of short spoon-shaped stubby teeth around the front of the mouth would
serve to bite or pull off soft leaves and water-plants, but the animal
evidently could not masticate its food, and must have swallowed it
without chewing as do modern reptiles and birds.

"The brain-case occupies only a small part of the back of the skull,
so that the brain must have been small even for a reptile, and its
organization (as inferred from the form of the brain-case) indicates a
very low grade of intelligence. Much larger than the brain proper was
the spinal cord, especially in the region of the sacrum, controlling
most of the reflex and involuntary actions of the huge organism. Hence
we can best regard the Brontosaurus as a great, slow-moving animal
automaton, a vast storehouse of organized matter directed chiefly or
solely by instinct, and to a very limited degree, if at all, by
conscious intelligence. Its huge size and its imperfect organization,
compared with the great quadrupeds of today, rendered its movements
slow and clumsy; its small and low brain shows that it must have been
automatic, instinctive and unintelligent."

_Composition of the Brontosaurus Skeleton._ "The principal specimen,
No. 460, is from the Nine Mile Crossing of the Little Medicine Bow
River, Wyoming. It consists of the 5th, 6th, and 8th to 13th cervical
vertebrae, 1st to 9th dorsal and 3rd to 19th caudal vertebrae, all the
ribs, both coracoids, parts of sacrum and ilia, both ischia and pubes,
left femur and astragalus, and part of left fibula. The backbone and
most of the neck of this specimen were found articulated together in
the quarry, the ribs of one side in position, the remainder of the
bones scattered around them, and some of the tail bones weathered out
on the surface.

"From No. 222, found at Como Bluffs, Wyo., were supplied the right
scapula, 10th dorsal vertebra, and right femur and tibia.

"No. 339, from Bone-Cabin Quarry, Wyoming, supplied the 20th to 40th
caudal vertebrae, No. 592, from the same locality the metatarsals of
the right hind foot; and a few toe bones are supplied from other
specimens.

  [Illustration: Fig. 23.--Skull of _Diplodocus_ from Bone-Cabin
  Quarry, north of Medicine Bow, Wyoming.]

"The remainder of the skeleton is modelled in plaster, the scapula,
humerus, radius and ulna from the skeleton in the Yale Museum, the
rest principally from specimens in our own collections. The modelling
of the skull is based partly upon specimens in the Yale Museum, but
principally upon the complete skull of Morosaurus shown in another
case.

"Mounted by A. Hermann, completed Feb. 10, 1905."

_Diplodocus._ The _Diplodocus_ nearly equalled the Brontosaurus in
bulk and exceeded it in length. A skeleton in the Carnegie Museum at
Pittsburgh measures 87 feet in total length; although the mount is
composed from several individuals these proportions are probably not
far from correct. The skull is smaller and differently shaped and the
teeth are of quite different type. In the American Museum of Natural
History, a partial skeleton is exhibited in the wall case to the left
of the entrance of the Dinosaur Hall, and in an A-case near by are
skulls of _Diplodocus_ and _Morosaurus_ and a model of the skull of
_Brontosaurus_. The Diplodocus skull is widely different from the
other two in size and proportions and in the characters of teeth.

When the first remains of these amphibious Dinosaurs were found in the
Oxford Clays of England, they were considered by Richard Owen to be
related to the Crocodiles, and named Opisthocoelia. Subsequently the
finding of complete skeletons in this country led Cope and Marsh to
place them with the true Dinosaurs and the latter named them
Sauropoda.[13] Remains of these animals have also been found in India,
in German East Africa, in Madagascar, and in South America, so that
they were evidently widely distributed. In the Northern world they
survived until the Comanchic or Lower Cretaceous Period, but in the
southern continents they may have lived on into the Upper Cretaceous
or true Cretacic. Some of the remains recently found in German East
Africa indicate an animal exceeding either _Brontosaurus_ or
_Diplodocus_ in bulk.

  [Illustration: Fig. 24.--The Largest Known Dinosaur. Sketch
  reconstruction of _Brachiosaurus_, from specimens in the Field
  Museum in Chicago, and the Natural History Museum in Berlin.]

At the date of writing this handbook only preliminary accounts have
been given of the marvellous finds made near Tendaguru by the
expedition from Berlin. From these it appears that in length of neck
and fore limb this East African Dinosaur greatly exceeded either
_Brontosaurus_ or _Diplodocus_. The hinder parts of the skeleton
however, were relatively small. The proportions and measurements given
tally closely with the American _Brachiosaurus_, a gigantic sauropod
whose incomplete remains are preserved in the Field Museum in Chicago
and to this genus the Berlin authorities now refer their largest and
finest skeleton. If the Berlin specimens are correctly referred to
_Brachiosaurus_ they indicate an animal somewhat exceeding
_Diplodocus_ or _Brontosaurus_ in total bulk but distinguished by much
longer fore limbs and an immensely long neck--a giraffe-like wader
adapted to take refuge in deeper waters, more out of reach of the
fierce carnivores of the land.[14]

FOOTNOTES:

[Footnote 11: The mounted Skeleton of Brontosaurus, by W.D. Matthew,
Amer. Mus. Jour. Vol. v, pp. 63-70, figs. 1-5.]

[Footnote 12: Professor Williston makes the following criticism of
this theory:

   "I cannot agree with this view--the animals _must_ have laid
   their eggs upon land--for the reason that reptile eggs cannot
   hatch in water. S.W.W."

But with deference to Williston's high authority I may note that there
is no evidence that the Sauropoda were egg-laying reptiles. They, or
some of them, may have been viviparous like the Ichthyosaurus.]

[Footnote 13: European palaeontologists, especially Huxley and Seeley
in England, had also recognized their true relationships, and Seeley's
term Cetiosauria has precedence over Sauropoda, although the latter is
in common use.]

[Footnote 14: It is of interest to observe that in this group of
Sauropoda, the Brachiosauridæ, the neural spines of the vertebrae are
much simpler and narrower than in the Brontosaurus and Diplodocus. The
attachments were thus less extensive for the muscles of the back,
indicating that these muscles were less powerful. This difference is
correlated by Professor Williston with the longer fore limbs of the
Brachiosaurus, as signifying that the animal was less able, as indeed
he had less need, to rise up upon the hind limbs, in comparison with
Diplodocus or Brontosaurus in which the fore limbs were relatively
short.]



CHAPTER VI.

THE BEAKED DINOSAURS.

ORDER ORTHOPODA (ORNITHISCHIA OR PREDENTATA.)


The peculiar feature of this group of Dinosaurs is the horny beak or
bill. The bony core sutured to the front of the upper and lower jaws
was covered in life by a horny sheath, as in birds or turtles. But
this is not the only feature in which they came nearer to birds than
do the other Dinosaurs. The pelvic or hip bones are much more
bird-like in many respects, especially the backward direction of the
pubic bone, the presence of a prepubis, in the number of vertebrae
coössified into a solid sacrum, in the proportions of the ilium and so
on. Various features in the anatomy of the head, shoulder-blades and
hind limbs are equally suggestive of birds, and it seems probable that
the earliest ancestors of the birds were very closely related to the
ancestors of this group of Dinosaurs. But the ancestral birds became
adapted to flying, the ancestral Predentates to terrestrial life, and
in their later development became as widely diversified in form and
habits as the warm-blooded quadrupeds which succeeded them in the Age
of Mammals.

  [Illustration: Fig. 25.--Skulls of Iguanodont and Trachodont
  Dinosaurs. _Iguanodon_ and _Camptosaurus_ of the Jurassic and
  Comanchic; _Kritosaurus_ and _Corythosaurus_ of the Middle
  Cretacic (Belly River); _Saurolophus_ of the late Cretacic
  (Edmonton); _Trachodon_ of the latest Cretacic (Lance). The
  Iguanodon is European, the others North American. All 1/25 natural
  size.]

These Beaked Dinosaurs were, so far as we can tell, all vegetarians.
Unlike the birds, they retained their teeth and in some cases
converted them into a grinding apparatus which served the same purpose
as the grinders of herbivorous quadrupeds. It is interesting to
observe the different way in which this result is attained. In the
mammals the teeth, originally more complex in construction and fewer
in number, are converted into efficient grinders by infolding and
elongation of the crown of each tooth so as to produce on the wearing
surface a complex pattern of enamel ridges with softer dentine or
cement intervening, making a series of crests and hollows continually
renewed during the wear of the tooth. In the reptile the teeth,
originally simple in construction but more numerous and continually
renewed as they wear down and fall out,[15] are banked up in several
close packed rows, the enamel borders and softer dentine giving a
wearing surface of alternating crests and hollows continually renewed,
and reinforced from time to time, by the addition of new rows of teeth
to one side, as the first formed rows wear down to the roots. This is
the best illustrated in the _Trachodon_ (see fig. 27); the other
groups have not so perfect a mechanism.


A. THE IGUANODONTS: IGUANODON, CAMPTOSAURUS.

_Sub-Order Ornithopoda or Iguanodontia._

In the early days of geology, about the middle of the nineteenth
century, bones and footprints of huge extinct reptiles were found in
the rocks of the Weald in south-eastern England. They were described
by Mantell and Owen and shown to pertain to an extinct group of
reptiles which Owen called the Dinosauria. So different were these
bones from those of any modern reptiles that even the anatomical
learning of the great English palaeontologist did not enable him to
place them all correctly or reconstruct the true proportions of the
animal to which they belonged. With them were found associated the
bones of the great carnivorous dinosaur _Megalosaurus_; and the weird
reconstructions of these animals, based by Waterhouse Hawkins upon the
imperfect knowledge and erroneous ideas then prevailing, must be
familiar to many of the older readers of this handbook. Life size
restorations of these and other extinct animals were erected in the
grounds of the Crystal Palace at Sydenham, London, and in Central
Park, New York. Those in London still exist, so far as the writer is
aware, but the stern mandate of a former mayor of New York ordered the
destruction of the Central Park models, not indeed as incorrect
scientifically, but as inconsistent with the doctrines of revealed
religion, and they were accordingly broken up and thrown into the
waters of the Park lake. Small replicas of these early attempts at
restoring dinosaurs may still be seen in some of the older museums in
this country and abroad.

  [Illustration: Fig. 26.--SKELETON OF CAMPTOSAURUS, AN AMERICAN
  RELATIVE OF THE IGUANODON.]

The real construction of the Iguanodon was gradually built up by later
discoveries, and in 1877 an extraordinary find in a coal mine at
Bernissart in Belgium brought to light no less than seventeen
skeletons more or less complete. These were found in an ancient
fissure filled with rocks of Comanchic age, traversing the
Carboniferous strata in which the coal seam lay, and with them were
skeletons of other extinct reptiles of smaller size. The open fissure
had evidently served as a trap into which these ancient giants had
fallen, and either killed by the fall or unable to escape from the
pit, their remains had been subsequently covered up by sediments and
the pit filled in to remain sealed up until the present day. These
skeletons, unique in their occurrence and manner of discovery, are the
pride of the Brussels Museum of Natural History, and, together with
the earlier discoveries, have made the _Iguanodon_ the most familiar
type of dinosaur to the people of England and Western Europe.

  [Illustration: Fig. 27.--Teeth of the duck-billed dinosaur
  _Trachodon_. The dental magazine has been removed from the lower
  jaw and is seen to consist of several close-set rows of numerous
  small pencil-like teeth which are pushed up from beneath as they
  wear off at the grinding surface.]

_Camptosaurus._ The American counterpart of the Iguanodons of Europe
was the _Camptosaurus_, nearly related and generally similar in
proportions but including mostly smaller species, and lacking some of
the peculiar features of the Old World genus. In the National Museum
at Washington, are mounted two skeletons of _Camptosaurus_, a large
and a small species, and in the American Museum a skeleton of a small
species. It suggests a large kangaroo in size and proportions, but the
three-toed feet, with hoof-like claws, the reptilian skull, loosely
put together, with lizard-like cheek teeth and turtle beak indicate a
near relative of the great _Iguanodon_.

_Thescelosaurus._ The Iguanodont family survived until the close of
the Age of Reptiles, with no great change in proportions or
characters. Its latest member is _Thescelosaurus_, a contemporary of
_Triceratops_. Partial skeletons of this animal are shown in the
Dinosaur Hall; a more complete one is in the National Museum.

FOOTNOTES:

[Footnote 15: Trachodont teeth never drop out, they are completely
consumed. Only in the Iguanodonts and Ceratopsia are they shed.--B.
Brown.]



CHAPTER VII.

THE BEAKED DINOSAURS (Continued).

B. THE DUCK BILLED DINOSAURS,--TRACHODON, SAUROLOPHUS, ETC.

_Sub-Order Ornithopoda; Family Trachodontidæ._


These animals of the Upper Cretaceous are probably descended from the
Iguanodonts of an older period. But the long ages that intervened,
some millions of years, have brought about various changes in the
race, not so much in general proportions as in altering the form and
relations of various bones of skull and skeleton and perfecting their
adaptation to a somewhat different habit of life, so that they must be
regarded as descendants perhaps, but certainly rather distant
relatives, of the older group.

We know more about the Trachodonts than any other dinosaurs. For not
only are the skeletons more frequently found articulated, but parts of
the skin are not uncommonly preserved with them, and in one specimen
at least, so much of the skin is preserved that it may fairly be
called a "dinosaur mummy." This specimen of _Trachodon_ is in the
American Museum, and beside it are two fine mounted skeletons of the
largest size. There is also on exhibition a panel mount of a nearly
related genus, _Saurolophus_ the skeleton lying as it was found in the
rock, and a fine skeleton of a third genus _Corythosaurus_ with the
skin partly preserved on both sides of the crushed and flattened body
stands beside it. In the _Tyrannosaurus_ group when completed will
appear a fourth skeleton of the _Trachodon_. Several skulls and
incomplete skeletons on exhibition and other skeletons not yet
prepared add to the Museum collection of this group. Trachodon
skeletons may also be found in the Museums of New Haven, Washington,
Frankfurt-on-the-Main, London and Paris, but nowhere a series
comparable to that displayed at the American Museum.


THE TRACHODON GROUP.

The following description of the Trachodon group is by Mr. Barnum
Brown and first appeared in the American Museum Journal for April
1908:[16]

"This group takes us back in imagination to the Cretaceous period,
more than three millions of years ago, when Trachodonts were among the
most numerous of the dinosaurs. Two members of the family are
represented here as feeding in the marshes that characterized the
period, when one is startled by the approach of a carnivorous
dinosaur, Tyrannosaurus, their enemy, and rises on tiptoe to look over
the surrounding plants and determine the direction from which it is
coming. The other Trachodon, unaware of danger, continues peacefully
to crop the foliage. Perhaps the erect member of the group had already
had unpleasant experiences with hostile beasts, for a bone of its left
foot bears three sharp gashes which were made by the teeth of some
carnivorous dinosaur.

  [Illustration: Fig. 28.--Mounted Skeletons of _Trachodon_ in the
  American Museum. Height of standing skeleton 16 feet, 10 inches.]

"By thus grouping the skeletons in lifelike attitudes, the relation of
the different bones can best be shown, but these of course are only
two of the attitudes commonly taken by the creatures during life.
Mechanical and anatomical considerations, especially the long straight
shafts of the leg bones, indicate that dinosaurs walked with their
limbs straight under the body, rather than in a crawling attitude with
the belly close to the ground, as is common among living reptiles.

"Trachodonts lived near the close of the Age of Reptiles in the Upper
Cretaceous and had a wide geographical distribution, their remains
having been found in New Jersey, Mississippi and Alabama, but more
commonly in Wyoming, Montana, and the Dakotas. A suggestion of the
great antiquity of these specimens is given by the fact that since the
animals died layers of rock aggregating many thousand feet in vertical
thickness have been deposited along the Atlantic coast.

"The bones of the erect specimen are but little crushed and a clear
conception of the proportions of the animal can best be obtained from
this specimen. It will be seen that the Trachodon was shaped somewhat
like a kangaroo, with short fore legs, long hind legs, and a long
tail. The fore limbs are reduced indeed to about one-sixth the size of
the hind limbs and judging from the size and shape of the foot bones
the front legs could not have borne much weight. They were probably
used in supporting the anterior portion of the body when the creature
was feeding, and in aiding it to recover an upright position. The
specimen represented as feeding is posed so that the fore legs carry
very little of the weight of the body. There are four toes on the
front foot but the thumb is greatly reduced and the fifth digit or
little finger, is absent." (Subsequent discoveries have shown that the
arrangement of the digits made by Marsh and followed in this skeleton
is incorrect. It is the first digit that is absent, and the fifth is
reduced.)

"The hind legs are massive and have three well developed toes ending
in broad hoofs. The pelvis is lightly constructed with bones elongated
like those of birds. The long deep compressed tail was particularly
adapted for locomotion in the water. It may also have served to
balance the creature when standing erect on shore. The broad expanded
lip of bone known as the fourth trochanter, on the inner posterior
face of the femur or thigh bone was for the attachment of powerful
tail muscles similar to those which enable the crocodile to move its
tail from side to side with such dexterity. This trochanter is absent
from the thigh bones of land-inhabiting dinosaurs with short tails,
such as _Stegosaurus_ and _Triceratops_. The tail muscles were
attached to the vertebrae by numerous rod-like tendons which are
preserved in position as fossils on the erect skeleton. Trachodonts
are thought to have been expert swimmers. Unlike other dinosaurs their
remains are frequently found in rocks that were formed under sea
water probably bordering the shores but nevertheless containing
typical sea shells.

"The elaborate dental apparatus is such as to show clearly that
Trachodonts were strictly herbivorous creatures. The mouth was
expanded to form a broad duck-like bill which during life was covered
with a horny sheath, as in birds and turtles. Each jaw is provided
with from 45 to 60 vertical and from 10 to 14 horizontal rows of
teeth, so that there were more than 2000 teeth altogether in both
jaws.

"Among living saurians, or reptiles, the small South American iguana
_Amblyrhynchus_ may be compared in some respects with the Trachodons
notwithstanding the difference in size. These modern saurians live in
great numbers on the shores of the Galapagos Islands off the coast of
Chile. They swim out to sea in shoals and feed exclusively on seaweed
which grows on the bottom at some distance from shore. The animal
swims with perfect ease and quickness by a serpentine movement of its
body and flattened tail, its legs meanwhile being closely pressed to
its side and motionless. This is also the method of propulsion of
crocodiles when swimming.

"The carnivorous or flesh-eating dinosaurs that lived on land, such as
_Allosaurus_ and _Tyrannosaurus_, were protected from foes by their
sharp biting teeth, while the land-living herbivorous forms were
provided with defensive horns, as in _Triceratops_, sharp spines as
in _Stegosaurus_ or were completely armored as in _Ankylosaurus_.
Trachodon was not provided with horns, spines or plated armor, but it
was sufficiently protected from carnivorous land forms by being able
to enter and remain in the water. Its skin was covered with small
raised scales, pentagonal in form on the body and tail, where they
were largest, with smaller reticulations over the joints but never
overlapping as in snakes or fishes. A Trachodon skeleton was recently
found with an impression of the skin surrounding the vertebrae which
is so well preserved that it gives even the contour of the tail as is
shown in the illustration (fig. 32).

"During the existence of the Trachodonts the climate of the northern
part of North America was much warmer than it is at present, the plant
remains indicating a climate for Wyoming and Montana similar to what
now prevails in Southern California. Palm leaves resembling the
palmetto of Florida are frequently found in the same rocks with these
skeletons. Here occur also such, at present, widely separated trees as
the gingko now native of China, and the Sequoia now native of the
Pacific Coast. Fruits and leaves of the fig tree are also common, but
most abundant among the plant remains are the Equisetae or horsetail
rushes, some species of which possibly supplied the Trachodons with
food.

  [Illustration: Fig. 29.--Restoration of the Duck-billed Dinosaur
  Trachodon. This restoration, made by Mr. Knight under supervision
  of Professor Osborn, embodies the latest evidence as to the
  structure and characteristic poses of these animals, the character
  of the skin and their probable habits and environment. _After
  Osborn_]

"Impressions of the more common plants found in the rocks of this
period with sections of the tree trunks showing the woody structure
will be [have been] introduced into the group as the ground on which
the skeletons stand. In the rivers and bayous of that remote period
there also lived many kinds of Unios or fresh-water clams, and other
shells, the casts of which are frequently found with Trachodon bones.
The fossil trunk of a coniferous tree was found in Wyoming, which was
filled with groups of wood-living shells similar to the living Teredo.
These also will be introduced in the ground-work.

"The skeleton mounted in a feeding posture was one of the principal
specimens in the Cope Collection, which, through the generosity of the
late President Jesup, was purchased and given to the American Museum.
It was found near the Moreau River, north of the Black Hills, South
Dakota, in 1882, by Dr. J.L. Wortman and Mr. R.S. Hill, collectors for
Professor Cope. The erect skeleton came from Crooked Creek, central
Montana, and was found by a ranchman, Mr. Oscar Hunter, while riding
through the bad lands with a companion in 1904. The specimen was
partly exposed, with backbone and ribs united in position. The parts
that were weathered out are much lighter in color than the other
bones. Their large size caused some discussion between the ranchmen
and to settle the question, Mr. Hunter dismounted and kicked off all
the tops of the vertebrae and rib-heads above ground, thereby proving
by their brittle nature that they were stone and not buffalo bones as
the other man contended. The proof was certainly conclusive, but it
was extremely exasperating to the subsequent collectors. Another
ranchman, Mr. Alfred Sensiba, heard of the find and knowing that it
was valuable 'traded' Mr. Hunter a six-shooter for his interest in it.
The specimen was purchased from Messrs. Sensiba Brothers and excavated
by the American Museum in 1906."

  [Illustration: Fig. 30.--THE DINOSAUR MUMMY. SKELETON OF A
  TRACHODON PRESERVING THE SKIN IMPRESSIONS OVER A LARGE PART OF THE
  BODY. _After Osborn_]


THE DINOSAUR "MUMMY."

We all _believe_ that the Dinosaurs existed. But to realize it is not
so easy. Even with the help of the mounted skeletons and restorations,
they are somewhat unreal and shadowy beings in the minds of most of
us. But this "dinosaur mummy" sprawling on his back and covered with
shrunken skin--a real specimen, not restored in any part--brings home
the reality of this ancient world even as the mummy of an ancient
Egyptian brings home to us the reality of the world of the Pharaohs.
The description of this unique skeleton by Professor Henry Fairfield
Osborn first appeared in the Museum Journal for January 1911.[17]

"Two years ago (1908) through the Jesup Fund, the Museum came into
possession of a most unique specimen discovered in August 1908, by the
veteran fossil hunter Charles H. Sternberg of Kansas. It is a large
herbivorous dinosaur of the closing period of the Age of Reptiles and
is known to palaeontologists as _Trachodon_ or more popularly as the
'duck-billed dinosaur.'

"The skeleton or hard parts of these very remarkable animals had been
known for over forty years, and a few specimens of the epidermal
covering, but it was not until the discovery of the Sternberg specimen
that a complete knowledge of the outer covering of these dinosaurs was
gained. It appears probable that in a number of cases these priceless
skin impressions were mostly destroyed in removing the fossil
specimens from their surroundings because the explorers were not
expecting to find anything of the kind. Altogether seven specimens
have been discovered in which these delicate skin impressions were
partly preserved, but the 'Trachodon mummy' far surpasses all the
others, as it yields a nearly complete picture of the outer covering.

"The reason the Sternberg specimen (_Trachodon annectens_) may be
known as a dinosaur 'mummy' is that in all the parts of the animal
which are preserved (_i.e._ all except the hind limbs and the tail),
the epidermis is shrunken around the limbs, tightly drawn along the
bony surfaces, and contracted like a great curtain below the chest
area. This condition of the epidermis suggests the following theory of
the deposition and preservation of this wonderful specimen, namely:
that after dying a natural death the animal was not attacked or preyed
upon by its enemies, and the body lay exposed to the sun entirely
undisturbed for a long time, perhaps upon a broad sand flat of a
stream in the low-water stage; the muscles and viscera thus became
completely dehydrated, or desiccated by the action of the sun, the
epidermis shrank around the limbs, was tightly drawn down along all
the bony surfaces, and became hardened and leathery, on the abdominal
surfaces the epidermis was certainly drawn within the body cavity,
while it was thrown into creases and folds along the sides of the body
owing to the shrinkage of the tissues within. At the termination of a
possible low-water season during which these processes of desiccation
took place, the 'mummy' may have been caught in a sudden flood,
carried down the stream and rapidly buried in a bed of fine river sand
intermingled with sufficient elements of clay to take a perfect cast
or mold of all the epidermal markings before any of the epidermal
tissues had time to soften under the solvent action of the water. In
this way the markings were indicated with absolute distinctness, ...
the visitor will be able by the use of the hand glass to study even
the finer details of the pattern, although of course there is no trace
either of the epidermis itself, which has entirely disappeared, or of
the pigmentation or coloring, if such existed.

"Although attaining a height of fifteen to sixteen feet the trachodons
were not covered with scales or a bony protecting armature, but with
dermal tubercles of relatively small size, which varied in shape and
arrangement in different species, and not improbably associated with
this varied epidermal pattern there was a varied color pattern. The
theory of a color pattern is based chiefly upon the fact that the
larger tubercles concentrate and become more numerous on all those
portions of the body exposed to the sun, that is, on the outer
surfaces of the fore and hind limbs, and appear to increase also along
the sides of the body and to be more concentrated on the back. On the
less exposed areas, the under side of the body and the inner sides of
the limbs, the smaller tubercles are more numerous, the larger
tubercles being reduced to small irregularly arranged patches. From
analogy with existing lizards and snakes we may suppose, therefore,
that the trachodons presented a darker appearance when seen from the
back and a lighter appearance when seen from the front.

  [Illustration: Fig. 31.--The Dinosaur Mummy. Detail of skin of
  under side of body. _After Osborn_]

  [Illustration: Fig. 32.--Skin impression from the tail of a
  _Trachodon_. The impressions appear to have been left by horny
  scutes or scales, not overlapping like the scales on the body of
  most modern reptiles, but more like the scutes on the head of a
  lizard.]

  [Illustration: Fig. 33.--Skull of Gila Monster (_Heloderma_), for
  comparison of surface with skin impressions of _Trachodon_.
  Enlarged to 4/3.]

"The thin character of the epidermis as revealed by this specimen
favors also the theory that these animals spent a large part of their
time in the water, which theory is strengthened by the fact that the
diminutive fore limb terminates not in claws or hoofs, but in a broad
extension of the skin, reaching beyond the fingers and forming a kind
of paddle.[18] The marginal web which connects all the fingers with
each other, together with the fact that the lower side of the fore
limb is as delicate in its epidermal structure as the upper,
certainly tends to support the theory of the swimming rather than the
walking or terrestrial function of this fore paddle as indicated in
the accompanying preliminary restoration that was made by Charles R.
Knight working under the writer's direction. One is drawn in the
conventional bipedal or standing posture while the other is in a
quadrupedal pose or walking position, sustaining or balancing the fore
part of the body on a muddy surface with its fore feet. In the distant
water a large number of animals are disporting themselves.

"The designation of these animals as the 'duck-billed' dinosaurs in
reference to the broadening of the beak, has long been considered in
connection with the theory of aquatic habitat. The conversion of the
fore limb into a sort of paddle, as evidenced by the Sternberg
specimen, strengthens this theory.

"This truly wonderful specimen, therefore, nearly doubles our previous
insight into the habits and life of a very remarkable group of
reptiles."

_Saurolophus, Corythosaurus._ In the latest Cretaceous formation, the
Lance or Triceratops beds, all the duck-billed dinosaurs are much
alike, and are referred to the single genus _Trachodon_. In somewhat
older formations of the Cretacic period there were several different
kinds. _Saurolophus_ has a high bony spine rising from the top of the
skull; in _Corythosaurus_ there is a thin high crest like the crown of
a cassowary on top of the skull, and the muzzle is short and small
giving a very peculiar aspect to the head. Complete skeletons of these
two genera are exhibited in the Dinosaur Hall; the _Corythosaurus_ is
worthy of careful study, as the skin of the body, hind limbs and tail,
the ossified tendons, and even the impressions of the muscular tissues
in parts of the body and tail, are more or less clearly indicated.

  [Illustration: Fig. 34.--SKELETON OF SAUROLOPHUS, FROM UPPER
  CRETACIC OF ALBERTA. _After Brown_]

These Duck-billed Dinosaurs probably ranged all over North America and
the northerly portions of the Old World during the later Cretacic.
Fragmentary remains have been found in New Jersey and southward along
the Atlantic coast. A partial skeleton was described many years ago by
Leidy under the name of _Hadrosaurus_ and restored and mounted in the
museum of the Philadelphia Academy of Sciences. _Telmatosaurus_ of the
Gosau formation in Austria also belongs to this group, and fragmentary
remains have been found in the upper Cretacic of Belgium, England and
France.

FOOTNOTES:

[Footnote 16: Brown, Barnum. "The Trachodon Group." Amer. Mus. Jour.
Vol. viii, pp. 51-56, plate and 3 text figs., 1908.]

[Footnote 17: Osborn, Henry Fairfield, "Dinosaur Mummy" Amer. Mus.
Jour. Vol. xi, pp. 7-11, illustrated, Jan. 1911.]

[Footnote 18: There is some doubt whether this was really the
condition during life. W.D.M.]



CHAPTER VIII.

THE BEAKED DINOSAURS (Continued.)

C. THE ARMORED DINOSAURS--STEGOSAURUS, ANKYLOSAURUS.

_Sub-Order Stegosauria._


This group of dinosaurs is most remarkable for the massive bony armor
plates, crests or spines covering the body and tail. They were more or
less completely quadrupedal instead of bipedal, with straight
post-like limbs and short rounded hoofed feet adapted to support the
weight of the massive body and heavy armature. Although so different
superficially from the bird-footed biped Iguanodonts they are
evidently related to them, for the teeth are similar, and the horny
beak, the construction of the pelvis, the three-toed hind foot and
four-toed front foot all betray relationship. From what we know of
them it seems probable that they evolved from Iguanodont ancestors,
developing the bony armor as a protection against the attacks of
carnivorous dinosaurs, and modifying the proportions of limbs and feet
to enable them to support its weight. They were evidently herbivorous
and some of them of gigantic size. Smaller kinds with less massive
armor have been found in Europe but the largest and most extraordinary
members of this strange race are from North America.


STEGOSAURUS.

This extraordinary reptile equalled the Allosaurus in size, and bore
along the crest of the back a double row of enormous bony plates
projecting upward and somewhat outward alternately to one side and the
other. The largest of these plates situated just back of the pelvis
were over two feet high, two and a half long, thinning out from a base
four inches thick. The tail was armed with four or more stout spines
two feet long and five or six inches thick at the base. In the neck
region and probably elsewhere the skin had numerous small bony nodules
and some larger ones imbedded in its substance or protecting its
surface. The head was absurdly small for so huge an animal, and the
stiff thick tail projected backward but was not long enough to reach
the ground. The hind limbs are very long and straight, the fore limbs
relatively short, and the short high arched back and extremely deep
and compressed body served to exaggerate the height and prominence of
the great plates. The surface of these plates, covered with a network
of blood-vessels, shows that they bore a covering of thick horny skin
during life, which probably projected as a ridge beyond their edges
and still further increased their size. The spines of the tail, also,
were probably cased in horn.

This extraordinary animal was a contemporary of the Brontosaurus and
Allosaurus, and its discovery was one of the great achievements of the
late Professor Marsh. The skeletons which he described are mounted in
the Yale and National Museums. Another skeleton was found in the
famous Bone-Cabin Quarry, near Medicine Bow, Wyoming, by the American
Museum Expedition of 1901. This skeleton, at present withdrawn from
lack of space, will be mounted in the Jurassic Dinosaur Hall in the
new wing now under construction.

  [Illustration: Fig. 35.--Skull and lower jaw of Armored Dinosaur
  _Ankylosaurus_, from Upper Cretacic (Edmonton formation) of
  Alberta. Left side view. _After Brown_]


ANKYLOSAURUS.

Related to _Stegosaurus_, equally huge, but very different in
proportions and character of its armor was the Ankylosaurus of the
late Cretacic. This animal, a contemporary of the Tyrannosaurus and
duck-billed dinosaurs was more effectively though less grotesquely
armored than its more ancient relative. The body is covered with
massive bony plates set close together and lying flat over the surface
from head to tip of tail. While the stegosaur's body was narrow and
compressed, in this animal it is exceptionally broad and the wide
spreading ribs are coössified with the vertebrae, making a very solid
support for the transverse rows of armor plates. The head is broad
triangular, flat topped and solidly armored, the plates consolidated
with the surface of the skull and overhanging sides and front, the
nostrils and eyes overhung by plates and bosses of bone; and the tail
ended in a blunt heavy club of massive plates consolidated to each
other and to the tip of the tail vertebrae. The legs were short,
massive and straight, ending probably in elephant-like feet. The
animal has well been called "the most ponderous animated citadel the
world has ever seen" and we may suppose that when it tucked in its
legs and settled down on the surface it would be proof even against
the attacks of the terrible Tyrannosaur.

  [Illustration: Fig. 36.--_Ankylosaurus_, top view of skull in fig.
  35. _After Brown_]

This marvellous animal was made known to science by the discoveries of
the Museum parties in Montana and Alberta under Barnum Brown.
Fragmentary remains of smaller relatives had been discovered by
earlier explorers but nothing that gave any adequate notion of its
character or gigantic size. From a partial skeleton discovered in the
Hell Creek beds of Montana, and others in the Edmonton and Belly River
formations of the Red Deer River, Alberta, it has been possible to
reconstruct the entire skeleton of the animal, save for the feet, and
to locate and arrange most of the armor plates exactly. A skeleton
mount from these specimens will shortly be constructed for the
Cretaceous Dinosaur Hall.

_Scelidosaurus, Polacanthus, etc._ Various armored dinosaurs, of
smaller size and less heavily plated, have been described from the
Jurassic, Comanchic and Cretacic formations of Europe. The best known
are _Scelidosaurus_ of the Lower Jurassic of England, and
_Polacanthus_ of the Comanchic (Wealden). _Stegopelta_ of the
Cretaceous of Wyoming is more nearly related to _Ankylosaurus_.



CHAPTER IX.

THE BEAKED DINOSAURS (Concluded.)

D. THE HORNED DINOSAURS, TRICERATOPS, ETC.

_Sub-Order Ceratopsia._


In 1887 Professor Marsh published a brief notice of what he supposed
to be a fossil bison horn found near Denver, Colorado. Two years later
the explorations of the lamented John B. Hatcher in Wyoming and
Montana resulted in the unexpected discovery that this horn belonged
not to a bison but to a gigantic horned reptile, and that it belonged
not in the geological yesterday as at first thought, but in the far
back Cretacic, millions of years ago. For Mr. Hatcher found complete
skulls, and later secured skeletons, clearly of the Dinosaurian group,
but representing a race of dinosaurs whose existence, or at least
their extraordinary character, had been quite unsuspected. It appeared
indeed that certain teeth and skeleton bones previously discovered by
Professor Cope were related to this new type of dinosaur, but the
fragments known to the Philadelphia professor gave him no idea of what
the animal was like, although with his usual acumen he had discerned
that they differed from any animal known to science and registered
them as new under the names of _Agathaumas_ 1873 and _Monoclonius_
1876. Professor Marsh re-named his supposed bison "_Ceratops_" (_i.e._
"horned face") and gave to the closely related skulls discovered by
Mr. Hatcher the name of _Triceratops_ (_i.e._ "three horned face"),
while to the whole group he gave the name of Ceratopsia.

  [Illustration: Fig. 37.--Skulls of Horned Dinosaurs. The lower
  row, _Ceratops_, _Styracosaurus_, _Monoclonius_, are from the
  Middle Cretacic (Belly River formation) of Alberta;
  _Anchiceratops_ is from the Upper Cretacic (Edmonton formation) of
  Alberta; _Triceratops_ and _Torosaurus_ from the uppermost
  Cretacic (Lance formation) of Wyoming.]

These were the first of a long series of discoveries which through
scientific and popular descriptions have made the Horned Dinosaurs
familiar to the world. Most of them are still very imperfectly known,
and of their evolution and earlier history we know very little as yet.
But we can form a fairly correct idea of their general appearance and
habits and of the part they played in the world of the late Cretacic.
So far as known they were limited to North America. The most striking
feature of the Horned Dinosaurs is the gigantic skull, armed with a
pair of horns over the orbits and a median horn on the nasal bones in
front, and with a great bony crest projecting at the back and sides.
In some species the skull with its bony frill attains a length of
seven or even eight feet and about three feet width; the usual length
is five or six feet and the width about three. In the best known
genus, _Triceratops_, the paired horns are long and stout and the
front horn quite short or almost absent, while in _Monoclonius_ these
proportions are reversed, the front horn being long while the paired
horns are rudimentary.

The teeth are in a single row but are broadened out into a wide
grinding surface. The animal was quadrupedal, with short massive limbs
and rounded elephantine feet tipped with hoofs, three in the hind
foot, four in the fore foot, a short massive tail that could hardly
reach the ground, a short broad-barrelled body and a short neck
completely hidden on top and sides by the overhanging bony frill of
the skull. In many respects these animals are suggestive far more than
any other dinosaurs, of the great quadrupeds of Tertiary and modern
times, rhinoceroses, hippopotami, titanotheres and elephants, as in
the horns they suggest the bison. For this reason although less
gigantic than the Brontosaurus or Tyrannosaurus, less grotesque
perhaps, than the Stegosaurus, they are more interesting than any
other dinosaurs. While thus departing far from the earlier type of the
beaked dinosaurs (the Iguanodonts) they are evidently descended from
them.

  [Illustration: Fig. 38.--Skull of _Triceratops_ from the Lance
  formation in Wyoming, one-eighteenth natural size. The length of
  the horns is 2 feet, 9-1/2 inches. The rostral bone or beak, and
  the lower jaw, are lacking; in the illustration on the cover they
  have been restored in outline. This fine skull was discovered by
  George M. Sternberg, and purchased for the Museum by Mr. Charles
  Lanier in 1909.]


TRICERATOPS.

This is the best known of the Horned Dinosaurs, as various skulls and
partial skeletons have been found from which it has been possible to
reconstruct the entire animal. There is a mounted skeleton in the
National Museum, another will shortly be mounted in the American
Museum, and there are skulls in several American and European
museums.

_Triceratops_ exceeded the largest rhinoceroses in bulk, equalling a
fairly large elephant, but with much shorter legs. The great horns
over the eyes projected forward or partly upward; in one of our skulls
they are 33-1/2 inches long. During life they were probably covered
with horn increasing the length by six inches or perhaps a foot. The
ball-like condyle for articulation of the neck lies far underneath, at
the base of the frill, almost in the middle of the skull.

  [Illustration: Fig. 39.--Skull of _Monoclonius_, a horned dinosaur
  from the Cretacic (Belly River formation) of Alberta.
  One-fifteenth natural size. The horns over the eyes are
  rudimentary, and the nasal horn large, reversing the proportions
  in _Triceratops_.]

_Monoclonius, Ceratops, etc._ The _Triceratops_ and another equally
gigantic Horned Dinosaur, _Torosaurus_, were the last survivors of
their race. In somewhat older formations of Cretacic age are found
remains of smaller kinds, some of them ancestors of these latest
survivors, others collaterally related. None of these have the bony
frill completely roofing over the neck as it does in _Triceratops_.
There is always a central spine projecting backwards and widening out
at the top to the bony margin of the frill which sweeps around on each
side to join bony plates that project from the sides of the skull top.
This encloses an open space or "fenestra," so that the neck was not
completely protected above. Sometimes the margin of the frill is
plain, at other times it carries a number of great spikes, like a
gigantic Horned Lizard (_Phrynosoma_).

  [Illustration: Fig. 40.--Outline sketch restoration of
  _Triceratops_, from the mounted skeleton in the National Museum.]

In _Ceratops_ the horns over the eyes are large and the nasal horn
small. In _Monoclonius_ the nasal horn is large and those over the
eyes are rudimentary. The great variety of species that has been found
in recent years shows that these Horned Dinosaurs were a numerous and
varied race of which as yet we know only a few. Of their evolution we
have little direct knowledge, but probably they are descended from the
Iguanodonts and Camptosaurs of the Comanchic, and their quadrupedal
gait, huge heads, short tails and other peculiarities are secondary
specializations, their ancestors being bipedal, long-tailed, small
headed and hornless.

The fine skulls of _Triceratops_, _Monoclonius_, _Ceratops_ and
_Anchiceratops_ in the Museum collections illustrate the variety of
these remarkable animals. Complete skeletons of the first two genera
are being prepared for mounting and exhibition.



CHAPTER X.

GEOGRAPHICAL DISTRIBUTION OF DINOSAURS.


Remains of Dinosaurs have been found in all the continents, but
chiefly in Europe and North America. Explorations in other parts of
the world have not as yet been sufficient to show whether or not each
continent developed especial kinds peculiar to it, nor to afford any
reliable evidence as to whether the relations of the continents were
different during the Mesozoic. Thus far, the Carnivorous group seems
most widespread, for it alone has been found in Australia. The
Sauropods or Amphibious Dinosaurs have been found in Europe, North
America, India, Madagascar, Patagonia, and Africa, sufficient to show
that their distribution was world wide with the possible exception of
Australia, and probable exception of most oceanic islands (few of the
modern oceanic islands existed at that time although there may well
have been many others no longer extant). The Beaked Dinosaurs are more
limited in their distribution, for none of them so far as at present
known reached Australia or South America. But in the present stage of
discovery it would be rash to conclude that they were surely limited
to the regions where they have been discovered. It is not wholly
clear as yet whether the Dinosaurian fauna that flourished at the end
of the Jurassic in the north survived to the Upper Cretacic in the
southern continents, but present evidence points that way, and
indicates that the girdle of ocean which during the Cretacic
depression encircled the northern world, formed a barrier which the
Cretacic dinosaurian fauna never succeeded in crossing.

The earlier groups of Beaked Dinosaurs are found in both Europe and
America, and in the Cretacic the Duck-billed and Armored groups are
represented in both regions. The Horned Dinosaurs, however, are known
with certainty only from North America.

While most of the important fossil specimens in this country have been
found in the West, more fragmentary remains have been found on the
Atlantic sea-board, and it is probable that they ranged all over the
intervening region, wherever they found an environment suited to their
particular needs.



CHAPTER XI.

COLLECTING DINOSAURS.

HOW AND WHERE THEY ARE FOUND.


The visitor who is introduced to the dinosaurs through the medium of
books and pictures or of the skeletons exhibited in the great museums,
finds it hard--well nigh impossible--to realize their existence.
However willing he may be to accept on faith the reconstructions of
the skeletons, the restorations of the animals and their supposed
environment, it yet remains to him somewhat of a fairy-tale, a
fanciful imaginative world peopled with ogres and dragons and
belonging to the unreal "once upon a time" which has no connection
with the ever present workaday world in which we live. Birds and
squirrels, rabbits and foxes belong to this real world because he has
seen them in his walks through the woods; even elephants and
rhinoceroses, though his acquaintance be limited to menagerie
specimens, seem fairly real--although one recalls the farmer's comment
on first seeing a giraffe in the Zoological park: "There aint no sich
animal." But dinosaurs--one easily realizes the state of mind that
prompts the inquiry so often made by visitors to the Dinosaur
Hall:--"they make these out of plaster, don't they?" So far as is
consistent with good taste, the aim of the American Museum has been
to enable the visitor to see for himself how much of plaster
reconstruction there is to each skeleton, and to explain in the labels
what the basis was for the reconstructed parts.

_How They are Found._ But to the collector these extinct animals are
real enough. As he journeys over the western plains he sees the
various living inhabitants thereof, birds and beasts, as well as men,
pursuing their various modes of life; here and there he comes across
the scattered skeletons or bones of modern animals lying strewn upon
the surface of the ground or half buried in the soil of a cut bank. In
the shales or sandstones that underlie the soil he finds the objects
of his search, skeletons or bones of extinct animals, similarly
disposed, but buried in rock instead of soft soil, and exposed in
cañons and gullies cut through the solid rock. Each rock formation, he
knows by precept and experience, carries its own peculiar fauna, its
animals are different from those of the formation above and from those
in the formation below. Days and weeks he may spend in fruitless
search following along the outcrop of the formation, through rugged
badlands, along steep cañon walls, around isolated points or buttes,
without finding more than a few fragments, but spurred on by vivid
interest and the rainbow prospect of some new or rare find. Finally
perhaps, after innumerable disappointments, a trail of fragments leads
up to a really promising prospect. A cautious investigation indicates
that an articulated skeleton is buried at this point, and that not
too much of it has "gone out" and rolled in weathered fragments down
the slope. For the tedious and delicate process of disinterring the
skeleton from the rock he will need to keep ever in mind the form and
relations of each bone, the picture of the skeleton as it may have
been when buried. The heavy ledges above are removed with pick and
shovel, often with help of dynamite and a team and scraper. As he gets
nearer to the stratum in which the bones lie the work must be more and
more careful. A false blow with pick or chisel might destroy
irreparably some important bony structure. Bit by bit he traces out
the position and lay of the bones, working now mostly with awl and
whisk-broom, uncovering the more massive portions, blocking out the
delicate bones in the rock, soaking the exposed surfaces repeatedly
with thin "gum" (mucilage) or shellac, channeling around and between
the bones until they stand out on little pedestals above the quarry
floor. Then, after the gum or shellac has dried thoroughly and
hardened the soft parts, and the surfaces of bone exposed are further
protected by pasting on a layer of tissue paper, it is ready for the
"plaster jacket." This consists of strips of burlap dipped in
plaster-of-paris and pasted over the surface of each block until top
and sides, all but the pedestal on which it rests, are completely
cased in, the strips being pressed and kneaded close to the surface of
the block as they are laid on. When this jacket sets and dries the
block is rigid and stiff enough to lift and turn over; the remains of
the pedestal are trimmed off and the under surface is plastered like
the rest. With large blocks it is often necessary to paste into the
jacket, on upper or both sides, boards, scantling or sticks of wood to
secure additional rigidity. For should the block "rack," or become
shattered inside, even though no fragments were lost, the specimen
would be more or less completely ruined.

  [Illustration: Fig. 41.--A Dinosaur skeleton, prospected and ready
  for encasing in plaster bandages and removal in blocks.
  (_Corythosaurus_, Red Deer River, Alberta.)]

The next stage will be packing in boxes with straw, hay or other
materials, hauling to the railway and shipment to New York.

Arrived at the Museum, the boxes are unpacked, each block laid out on
a table, the upper side of its plaster jacket softened with water and
cut away, and the preparation of the bone begins. Always it is more or
less cracked and broken up, but the fragments lie in their natural
relations. Each piece must be lifted out, thoroughly cleaned from rock
and dirt, and the fractured surfaces cemented together again. Parts of
bones, especially the interior, are often rotted into dust while the
harder outer surface is still preserved. The dust must be scraped out,
the interior filled with a plaster cement, and the surface pieces
re-set in position. Very often a steel rod is set into the plaster
filling the interior of a bone, to secure additional strength.

After this preparation is completed, each part being soaked repeatedly
with shellac until it will absorb no more, the bones can be handled
and laid out for study or exhibition. Then, if they are to be mounted
for a fossil skeleton, comes the work of restoring the missing parts.
For this a plaster composition is used.

Where only parts of one side are missing the corresponding parts of
the other side are used for model; where both sides are missing, other
individuals or nearly related species may serve as a guide. But it is
seldom wise to attempt restoration of a skeleton unless at least
two-thirds of it is present; composite skeletons made up of the
remains of several or many individuals, have been attempted, but they
are dangerous experiments in animals so imperfectly known as are most
of the dinosaurs. There is too much risk of including bones that
pertain to other species or genera, and of introducing thereby into
the restoration a more or less erroneous concept of the animal which
it represents. The same criticism applies to an overly large amount of
plaster restoration.

  [Illustration: Fig. 42.--Bone-Cabin Draw on Little Medicine River
  north of Medicine Bow, Wyoming. The location of the quarry is
  indicated by the stack of crated specimens on the left, and close
  to it the low sod-covered shack where the collecting party lived.
  Beyond the draw lies the flat rolling surface of the Laramie
  Plains and on the southern horizon the Medicine Bow Range with Elk
  Mountain at the center.]

In some instances the missing parts of a skeleton are not restored,
because, even though but a small part be gone, we have no good
evidence to guide in its reconstruction. This gives an imperfect and
sometimes misleading concept of what the whole skeleton was like, but
it is better than restoring it erroneously. Usually with the more
imperfect skeletons, a skull, a limb or some other characteristic
parts may be placed on exhibition but the remainder of the specimen is
stored in the study collections.

  [Illustration: Fig. 43.--American Museum party at Bone-Cabin
  Quarry, 1899. Seated, left to right Walter Granger, Professor H.F.
  Osborn, Dr. W.D. Matthew; standing, F. Schneider, Prof. R.S. Lull,
  Albert Thomson, Peter Kaison.]

_Where They are Found._ The chief dinosaur localities in this country
are along the flanks of the Rocky Mountains and the plains to the
eastward, from Canada to Texas. Not that dinosaurs were any more
abundant there than elsewhere. They probably ranged all over North
America, and different kinds inhabited other continents as well. But
in the East and the Middle West, the conditions were not favorable for
preserving their remains, except in a few localities. Formations of
this age are less extensive, especially those of the delta and
coast-swamps which the dinosaurs frequented. And where they do occur,
they are largely covered by vegetation and cannot be explored to
advantage. In the arid Western regions these formations girdle the
Rockies and outlying mountain chains for two-thousand miles from north
to south, and are extensively exposed in great escarpments, river
cañons and "badland" areas, bare of soil and vegetation and affording
an immense stretch of exposed rock for the explorer. Much of this area
indeed is desert, too far away from water to be profitably searched
under present conditions, or too far away from railroads to allow of
transportation of the finds at a reasonable expense. Fossils are much
more common in certain parts of the region, and these localities have
mostly been explored more or less thoroughly. But the field is far
from being exhausted. New localities have been found and old
localities re-explored in recent years, yielding specimens equal to or
better than any heretofore discovered. And as the railroad and the
automobile render new regions accessible, and the erosion of the
formations by wind and rain brings new specimens to the surface, we
may look forward to new discoveries for many years to come.

In other continents, except in Europe, there has been but little
exploration for dinosaurs. Enough is known to assure us that they will
yield faunæ no less extensive and remarkable than our own. We are in
fact only beginning to appreciate the vast extent and variety of these
records of a past world.

In a preceding chapter it was shown that the chief formations in which
dinosaur remains have been found belong to the end of the Jurassic and
the end of the Cretacic periods. The Jurassic dinosaur formations
skirt the Rockies and outlying mountain ranges but are often turned up
on edge and poorly exposed, or barren of fossils. The richest
collecting ground is in the Laramie Plains, between the Rockies and
the Laramie range in south-central Wyoming, but important finds have
also been made in Colorado and Utah. The Cretaceous Dinosaur
formations extend somewhat further out on the plains to the eastward,
and the best collecting regions thus far explored are in eastern
Wyoming, central Montana and in Alberta, Canada.


THE FIRST DISCOVERY OF DINOSAURS IN THE WEST.

_By Prof. S.W. Williston._

Most great discoveries are due rather to a state of mind, if I may use
such an expression, than to accident. The discovery of the immense
dinosaur deposits in the Rocky Mountains in March, 1877, may
truthfully be called great, for nothing in paleontology has equalled
it, and that it was made by three observers simultaneously can not be
called purely an accident. These discoverers were Mr. O. Lucas, then
a school teacher, later clergyman; Professor Arthur Lakes, then a
teacher in the School of Mines at Golden, Colorado; and Mr. William
Reed, then a section foreman of the Union Pacific Railroad at Como,
Wyoming, later the curator of paleontology of the University of
Wyoming--even as I write this, comes the notice of his death,--the
last. I knew them all, and the last two were long intimate friends.

In the autumn of 1878 I wrote the following:[19]

"The history of their discovery (the dinosaurs) is both interesting
and remarkable. For years the beds containing them had been studied by
geologists of experience, under the surveys of Hayden and King, but,
with the possible exception of the half of a caudal vertebra, obtained
by Hayden and described by Leidy as a species of _Poikilopleuron_, not
a single fragment had been recognized. This is all the more remarkable
from the fact that in several of the localities I have observed acres
literally strewn with fragments of bones, many of them extremely
characteristic and so large as to have taxed the strength of a strong
man to lift them. Three of the localities known to me are in the
immediate vicinity, if not upon the actual townsites of thriving
villages, and for years numerous fragments have been collected by (or
for) tourists and exhibited as fossil wood. The quantities hitherto
obtained, though apparently so vast, are wholly unimportant in
comparison with those awaiting the researches of geologists throughout
the Rocky Mountain region. I doubt not that many hundreds of tons will
eventually be exhumed." Rather a startling prophecy to make within
eighteen months of their discovery, but it was hardly exaggerated.

It is impossible to say which of these three observers actually made
the first discovery of Jurassic dinosaurs; whatever doubt there is is
in favor of Mr. Reed.

Professor Lakes, accompanied by his friend Mr. E.L. Beckwith, an
engineer, was, one day in March, 1877, hunting along the "hogback" in
the vicinity of Morrison, Colorado, for fossil leaves in the Dakota
Cretaceous sandstone which caps the ridge, when he saw a large block
of sandstone with an enormous vertebra partly imbedded in it. He
discussed the nature of the fossil with his friend (so he told me) and
finally concluded that it was a fossil bone. He had recently come from
England and had heard of Professor Phillips' discoveries of similar
dinosaurs there. He knew of Professor Marsh of Yale from his recent
discoveries of toothed birds in the chalk of Kansas, and reported the
find to him. As a result, the specimen, rock and all, was shipped to
him by express at ten cents a pound! And Professor Marsh immediately
announced the discovery of _Titanosaurus_ (_Atlantosaurus_) _immanis_,
a huge dinosaur having a probable length of one hundred and fifteen
feet and unknown height. And Professor Lakes was immediately set at
work in the "Morrison quarry" near by, whence comes the accepted name
of these dinosaur beds in the Rocky Mountains. Professor Lakes once
showed me the exact spot where he found his first specimen.

Mr. Lucas, teaching his first term of a country school that spring in
Garden Park near Cañon City, as an amateur botanist was interested in
the plants of the vicinity. Rambling through the adjacent hills in
search of them, in March, 1877, he stumbled upon some fragments of
fossil bones in a little ravine not far from the famous quarry later
worked for Professor Marsh. He recognized them as fossils and they
greatly excited, not only his curiosity, but the curiosity of the
neighbors. He had heard of the late Professor Cope and sent some of
the bones to him, who promptly labelled them _Camarasaurus supremus_.

The announcement of these discoveries promptly brought Mr. David
Baldwin, Professor Marsh's collector in New Mexico, to the scene. Only
a few months previously he had discovered fossil bones in the red beds
of New Mexico, the since famous Permian deposits. He naturally
explored the same beds at Cañon City, immediately below the dinosaur
deposits, and soon found the still very problematical _Hallopus_
skeleton, at their very top, a specimen which after nearly forty years
remains unique of its kind.

A few years earlier Professor Marsh, on his way east from the Tertiary
deposits of western Wyoming, had stopped at Como, Wyoming, to observe
the strange salamanders, or "fish with legs" as they were widely
known, so abundant in the lake at that place, about whose
transformations he later wrote a paper, perhaps the only one on modern
vertebrates that he ever published. While he was there Mr. Carlin, the
station agent, showed him some fossil bone fragments, so Mr. Reed told
me, that they had picked up in the vicinity, and about which Professor
Marsh made some comments. But he was so engrossed with the other
discoveries he was then making that he did not follow up the
suggestion. Had he done so the discovery of the "Jurassic Dinosaurs"
would have been made five years earlier.

Mr. Reed, tramping over the famous Como hills after game--he had been
a professional hunter of game for the construction camps of the Union
Pacific Railroad--in the winter and spring of 1877, observed some
fossil bones just south of the railway station that excited his
curiosity. But he and Mr. Carlin did not make their discovery known to
Professor Marsh till the following autumn, and then under assumed
names, fearing that they would be robbed of their discovery. I was
sent to Como in November of 1877 from Cañon City. I got off the train
at the station after midnight, and enquired for the nearest
hotel--(the station comprised two houses only), and where I could find
Messrs. Smith and Robinson. I was told that the section house was the
only hotel in the place and that these gentlemen lived in the country
and that there was no regular bus-line yet running to their ranch. A
freshly opened box of cigars, however, helped clear up things, and I
joined Mr. Reed the next day in opening "Quarry No. 1" of the Como
hills. Inasmuch as the mercury in the thermometer during the next two
months seldom reached zero--upward I mean--the opening of this famous
deposit was made under difficulties. That so much "head cheese," as we
called it, was shipped to Professor Marsh was more the fault of the
weather and his importunities than our carelessness. However, we found
some of the types of dinosaurs that have since become famous.

I joined Professor Lakes at the Morrison quarry in early September of
1877, and helped dig out some of the bones of _Atlantosaurus_. A few
weeks later I was sent to Cañon City to help Professor Mudge, my old
teacher, and Mr. Felch, who had begun work there in the famous "Marsh
Quarry". It was here that we found the type of _Diplodocus_.

The hind leg, pelvis and much of the tail of this specimen lay in very
orderly arrangement in the sandstone near the edge of the quarry, but
the bones were broken into innumerable pieces. After consultation we
decided that they were too much broken to be worth saving--and so most
of them went over into the dump. Sacrilege, doubtless, the modern
collector will say, but we did not know much about the modern methods
of collecting in those days, and moreover we were in too much of a
hurry to get the new discoveries to Yale College to take much pains
with them. I did observe that the caudal vertebrae had very peculiar
chevrons, unlike others that I had seen, and so I attempted to save
some samples of them by pasting them up with thick layers of paper.
Had we only known of plaster-of-paris and burlap the whole specimen
might easily have been saved. Later, when I reached New Haven, I took
off the paper and called Professor Marsh's attention to the strange
chevrons. And _Diplodocus_ was the result.

  [Illustration: Fig. 44.--The first dinosaur specimen found at
  Bone-Cabin Quarry. Hind limb of _Diplodocus_.]

My own connection with the discoveries of these old dinosaurs
continued only through the following summer, in Wyoming, when we added
the first mammals from the hills immediately back of the station, and
the types of some of the smaller dinosaurs, and when we explored the
vicinity for other deposits, on Rock Creek and in the Freeze Out
Mountains.

How many tons of these fossils have since been dug up from these
deposits in the Rocky Mountains is beyond computation. My prophecy of
hundreds of tons has been fulfilled; and they are preserved in many
museums of the world.

                    S.W. WILLISTON.


THE DINOSAURS OF THE BONE-CABIN QUARRY.[20]

_By Henry Fairfield Osborn._

One is often asked the questions: "How do you find fossils?" "How do
you know where to look for them?" One of the charms of the
fossil-hunter's life is the variety, the element of certainty combined
with the gambling element of chance. Like the prospector for gold, the
fossil-hunter may pass suddenly from the extreme of dejection to the
extreme of elation. Luck comes in a great variety of ways: sometimes
as the result of prolonged and deliberate scientific search in a
region which is known to be fossiliferous; sometimes in such a prosaic
manner as the digging of a well. Among discoveries of a highly
suggestive, almost romantic kind, perhaps none is more remarkable than
the one I shall now describe.

_Discovery of the Great Dinosaur Quarry._ In central Wyoming, at the
head of a "draw," or small valley, not far from the Medicine Bow
River, lies the ruin of a small and unique building, which marks the
site of the greatest "find" of extinct animals made in a single
locality in any part of the world. The fortunate fossil-hunter who
stumbled on this site was Mr. Walter Granger of the American Museum
expedition of 1897.

In the spring of 1898, as I approached the hillock on which the ruin
stands, I observed, among the beautiful flowers, the blooming cacti,
and the dwarf bushes of the desert, what were apparently numbers of
dark-brown boulders. On closer examination, it proved that there is
really not a single rock, hardly even a pebble, on this hillock; all
these apparent boulders are ponderous fossils which have slowly
accumulated or washed out on the surface from a great dinosaur bed
beneath. A Mexican sheep-herder had collected some of these petrified
bones for the foundations of his cabin, the first ever built of such
strange materials. The excavation of a promising outcrop was almost
immediately rewarded by finding a thigh-bone nearly six feet in length
which sloped downward into the earth, running into the lower leg and
finally into the foot, with all the respective parts lying in the
natural position as in life. This proved to be the previously unknown
hind limb of the great dinosaur _Diplodocus_.

In this manner the "Bone-Cabin Quarry" was discovered and christened.
The total contents of the quarry are represented in the diagram (not
reprinted.) It has given us, by dint of six successive years of hard
work, the materials for an almost complete revival of the life of the
Laramie region as it was in the days of the dinosaurs. By the aid of
workmen of every degree of skill, by grace of the accumulated wisdom
of the nineteenth century, by the constructive imagination, by the aid
of the sculptor and the artist, we can summon these living forms and
the living environment from the vasty deep of the past.

_The Famous Como Bluffs._ The circumstances leading up to our
discovery serve to introduce the story. From 1890 to 1897 we had been
steadily delving into the history of the Age of Mammals, in deposits
dating from two hundred thousand to three million years back, as we
rudely estimate geological time. In the course of seven years such
substantial progress had been made that I decided to push into the
history of the Age of Reptiles also, and, following the pioneers,
Marsh and Cope, to begin exploration in the period which at once marks
the dawn of mammalian life and the climax of the evolution of the
great amphibious dinosaurs.

In the spring of 1897 we accordingly began exploration in the heart of
the Laramie Plains, on the Como Bluffs. On arrival, we found numbers
of massive bones strewn along the base of these bluffs, tumbled from
their stratum above, too weather-worn to attract collectors, and
serving only to remind one of the time when these animals--the
greatest, by far, that nature has ever produced on land--were monarchs
of the world.

Aroused from sleep on a clear evening in camp by the heavy rumble of
a passing Union Pacific freight-train[21], I shall never forget my
meditations on the contrast between the imaginary picture of the great
Age of Dinosaurs, fertile in cycads and in a wonderful variety of
reptiles, and the present age of steam, of heavy locomotives toiling
through the semi-arid and partly desert Laramie Plains.

So many animals had already been removed from these bluffs that we
were not very sanguine of finding more; but after a fortnight our
prospecting was rewarded by finding parts of skeletons of the
long-limbed dinosaur _Diplodocus_ and of the heavy-limbed dinosaur
_Brontosaurus_. The whole summer was occupied in taking these animals
out for shipment to the East, the so-called "plaster method" of
removal being applied with the greatest success. Briefly, this is a
surgical device applied on a large scale for the "setting" of the
much-fractured bones of a fossilized skeleton. It consists in setting
great blocks of the skeleton, stone and all, in a firm capsule of
plaster subsequently reinforced by great splints of wood, firmly drawn
together with wet rawhide. The object is to keep all the fragments and
splinters of bone together until it can reach the skilful hands of the
museum preparator.

_The Rock Waves Connecting the Bluffs and the Quarry._ The Como Bluffs
are about ten miles south of the Bone-Cabin Quarry; between them is a
broad stretch of the Laramie Plains. The exposed bone layer in the two
localities is of the same age, and originally was a continuous level
stratum which may be designated as the "dinosaur beds;" but this
stratum, disturbed and crowded by the uplifting of the not far-distant
Laramie range of mountains and the Freeze Out Hills, was thrown into a
number of great folds or rock waves. Large portions, especially of the
upfolds, or "anticlines," of the waves, have been subsequently removed
by erosion; the edges of these upfolds have been exposed, thus
weathering out their fossilized contents, while downfolds are still
buried beneath the earth for the explorers of coming centuries.

Therefore, as one rides across the country to-day from the bluffs to
the quarry, startling the intensely modern fauna, the prong-horn
antelopes, jack-rabbits, and sage-chickens, he is passing over a vast
graveyard which has been profoundly folded and otherwise shaken up and
disturbed. Sometimes one finds the bone layer removed entirely,
sometimes horizontal, sometimes oblique, and again dipping directly
into the heart of the earth. This layer (dinosaur beds) is not more
than two hundred and seventy-four feet in thickness, and is altogether
of fresh-water origin; but as a proof of the oscillations of the
earth-level both before and after this great thin sheet of fresh-water
rock was so widely spread, there are evidences of the previous
invasion of the sea (ichthyosaur beds) and of the subsequent invasion
of the sea (mosasaur beds) in the whole Rocky Mountain region.

In traveling through the West, when once one has grasped the idea of
continental oscillation, or submergence and emergence of the land, of
the sequence of the marine and fresh-water deposits in laying down
these pages of earth-history, he will know exactly where to look for
this wonderful layer-bed of the giant dinosaurs; he will find that,
owing to the uplift of various mountain-ranges, it outcrops along the
entire eastern face of the Rockies, around the Black Hills, and in all
parts of the Laramie Plains; it yields dinosaur bones everywhere, but
by no means so profusely or so perfectly as in the two famous
localities we are describing.

_How the Skeletons Lie in the Bluffs and Quarry._ At the bluffs single
animals lie from twenty to one hundred feet apart; one rarely finds a
whole skeleton, such as that of Marsh's _Brontosaurus excelsus_, the
finest specimen ever secured here, which is now one of the treasures
of the Yale museum. More frequently a half or a third of a skeleton
lies together.

In the Bone-Cabin Quarry, on the other hand, we came across a
veritable Noah's-ark deposit, a perfect museum of all the animals of
the period. Here are the largest of the giant dinosaurs closely
mingled with the remains of the smaller but powerful carnivorous
dinosaurs which preyed upon them, also those of the slow and
heavy-moving armored dinosaurs of the period, as well as of the
lightest and most bird-like of the dinosaurs. Finely rounded, complete
limbs from eight to ten feet in length are found, especially those of
the carnivorous dinosaurs, perfect even to the sharply pointed and
recurved tips of their toes. Other limbs and bones are so crushed and
distorted by pressure that it is not worth while removing them.
Sixteen series of vertebræ were found strung together; among these
were eight long strings of tail-bones. The occurrence of these tails
is less surprising when we come to study the important and varied
functions of the tail in these animals, and the consequent connection
of the tail-bones by means of stout tendons and ligaments which held
them together for a long period after death. Skulls are fragile and
rare in the quarry, because in every one of these big skeletons there
were no fewer than ninety distinct bones which exceeded the head in
size, the excess in most cases being enormous.

  [Illustration: Fig. 45.--COLLECTING DINOSAURS AT BONE-CABIN
  QUARRY.
  a. The overlying soil and rocks are loosened with a pick and
  removed with team and scraper down to the fossil layer.

  b. The fossil layer is carefully prospected with small tools,
  chisels, awls and whisk brooms exposing the bones as they lie in
  the rocks.

  c. The blocks containing the fossils are channelled around,
  plastered over top and sides, undercut and carefully turned over
  and the under side trimmed and plastered.

  d. The blocks are then packed in boxes or crates with hay or any
  other available packing material.

  e. Boxes are loaded on wagons and hauled across country to the
  railroad.

  f. Boxes are finally loaded on cars and shipped through to New
  York City.]

The bluffs appear to represent the region of an ancient shoreline,
such conditions as we have depicted in the restoration of
_Brontosaurus_ (fig. 22)--the sloping banks of a muddy estuary or of a
lagoon, either bare tidal flats or covered with vegetation. Evidently
the dinosaurs were buried at or near the spot where they perished.

The Bone-Cabin Quarry deposit represents entirely different
conditions. The theory that it is the accumulation of a flood is, in
my opinion, improbable, because a flood would tend to bring entire
skeletons down together, distribute them widely, and bury them
rapidly. A more likely theory is that this was the area of an old
river-bar, which in its shallow waters arrested the more or less
decomposed and scattered carcasses which had slowly drifted
down-stream toward it, including a great variety of dinosaurs,
crocodiles, and turtles, collected from many points up-stream. Thus
were brought together the animals of a whole region, a fact which
vastly enhances the interest of this deposit.

_The Giant Herbivorous Dinosaurs._ By far the most imposing of these
animals are those which may be popularly designated as the great or
giant dinosaurs. The name, derived from _deinos_ terrible, and
_sauros_ lizard, refers to the fact that they appeared externally like
enormous lizards, with very long limbs, necks, and tails. They were
actually remotely related to the tuatera lizard of New Zealand, and
still more remotely to the true lizards.

No land animals have ever approached these giant dinosaurs in size,
and naturally the first point of interest is the architecture of the
skeleton. The backbone is indeed a marvel. The fitness of the
construction consists, like that of the American truss-bridge, in
attaining the maximum of strength with the minimum of weight. It is
brought about by dispensing with every cubic millimeter of bone which
can be spared without weakening the vertebræ for the various stresses
and strains to which they were subjected, and these must have been
tremendous in an animal from sixty to seventy feet in length. The
bodies of the vertebræ are of hour-glass shape, with great lateral and
interior cavities; the arches are constructed on the T-iron principle
of the modern bridge-builder, the back spines are tubular, the
interior is spongy, these devices being employed in great variety, and
constituting a mechanical triumph of size, lightness, and strength
combined. Comparing a great chambered dinosaurian (_Camarasaurus_)
vertebra (see above) with the weight per cubic inch of an ostrich
vertebra, we reach the astonishing conclusion that it weighed only
twenty-one pounds, or half the weight of a whale vertebra of the same
bulk. The skeleton of a whale seventy-four feet in length has recently
been found by Mr. F.A. Lucas of the Brooklyn Museum to weigh seventeen
thousand nine hundred and twenty pounds. The skeleton of a dinosaur of
the same length may be roughly estimated as not exceeding ten thousand
pounds.

_Proofs of Rapid Movements on Land._ Lightness of skeleton is a
walking or running or flying adaptation, and not at all a swimming
one; a swimming animal needs gravity in its skeleton, because
sufficient buoyancy in the water is always afforded by the lungs and
soft tissues of the body. The extraordinary lightness of these
dinosaur vertebræ may therefore be put forward as proof of supreme
fitness for the propulsion of an enormous frame during occasional
incursions upon land[22]. There are additional facts which point to
land progression, such as the point in the tail where the flexible
structure suddenly becomes rigid, as shown in the diagram of vertebræ
below; the component joints are so solid and flattened on the lower
surface that they seem to demonstrate fitness to support partly the
body in a tripodal position like that of a kangaroo. I have therefore
hazarded the view that even some of these enormous dinosaurs were
capable of raising themselves on their hind limbs, lightly resting on
the middle portion of the tail. In such a position the animal would
have been capable not only of browsing among the higher branches of
trees, but of defending itself against the carnivorous dinosaurs by
using its relatively short but heavy front limbs to ward off attacks.

There are also indications of aquatic habits in some of the giant
dinosaurs which render it probable that a considerable part of their
life was led in the water. One of these indications is the backward
position of the nostrils. Many, but not all, water-living mammals and
reptiles have the nostrils on top of the head, in order to breathe
more readily when the head is partly immersed. Another fact of note,
although perhaps less conclusive, is the fitness of the tail for use
while moving about in the water, if not in rapid swimming.

The great tail, measuring from twenty-eight to thirty feet, was one of
the most remarkable structures in these animals, and undoubtedly
served a great variety of purposes, propelling while in the water,
balancing and supporting and defending while on land. In _Diplodocus_
it was most perfectly developed from its muscular base to its delicate
and whip-like tip, perhaps for all these functions.

_The Three Kinds of Giant Dinosaurs._ It is very remarkable that three
distinct kinds of these great dinosaurs lived at the same time in the
same general region, as proved by the fact that their remains are
freely commingled in the quarry.

What were the differences in food and habits, in structure and in
gait, which prevented that direct and active competition between like
types in the struggle for existence which in the course of nature
always leads to the extermination of one or the other type? In the
last three years we have discovered very considerable differences of
structure which make it appear that these animals, while of the same
or nearly the same linear dimensions, did not enter into direct
competition either for food or for territory.

The dinosaur named _Diplodocus_ by Marsh is the most completely known
of the three. Our very first discovery in the Bone-Cabin Quarry gave
us the hint that _Diplodocus_ was distinguished by relatively long,
slender limbs, and that it may be popularly known as the "long-limbed
dinosaur." The great skeleton found in the Como Bluffs enabled me to
restore for the first time the posterior half of one of these animals
estimated as sixty feet in length, the hips and tail especially being
in a perfect state of preservation. A larger animal, nearer seventy
feet in length, including the anterior half of the body, and still
more complete, was discovered about ten miles north of the quarry, and
is now in the Carnegie Museum in Pittsburg. Combined, these two
animals have furnished a complete knowledge of the great bony frame.
The head is only two feet long, and is, therefore, small out of all
proportion to the great body. The neck measures twenty-one feet four
inches, and is by far the longest and largest neck known in any animal
living or extinct. The back is relatively very short, measuring ten
feet eight inches. The vertebræ of the hip measure two feet and three
inches. The tail measures from thirty-two to forty feet. We thus
obtain, as a moderate estimate of the total length of the animal,
sixty-eight to seventy feet. The restored skeleton, published by Mr.
J.B. Hatcher in July, 1901, and partly embodying our results, gave to
science the first really accurate knowledge of the length of these
animals, which hitherto had been greatly overestimated. The highest
point in the body was above the hips; here in fact, was the center of
power and motion, because, as observed above, the tail fairly balanced
the anterior part of the body.

The restoration by Mr. Knight is drawn from a very careful model made
under my direction, in which the proportions of the animal are
precisely estimated. It is, I think, accurate--for a restoration--as
well as interesting and up-to-date. These restorations are the
"working hypotheses" of our science; they express the present state of
our knowledge, and, being subject to modification by future
discoveries, are liable to constant change.

By contrast, the second type of giant dinosaur, the _Brontosaurus_, or
"thunder saurian" of Marsh, as shown in the restoration (fig. 22), was
far more massive in structure and relatively shorter in body. Five
more or less complete skeletons are now to be seen in the Yale,
American, Carnegie, and Field Columbian museums. In 1898 we discovered
in the bluffs, about three miles west of the Bone-Cabin Quarry, the
largest of these animals which has yet been found; it was worked out
with great care and is now being restored and mounted complete in the
American Museum. The thigh-bone is enormous, measuring five feet eight
inches in length, and is relatively of greater mass than that of
_Diplodocus_. The neck, chest, hips, and tail are correspondingly
massive. The neck is relatively shorter, however, measuring eighteen
feet, while in _Diplodocus_ it measures over twenty-one feet. The
total length of this massive specimen is estimated at sixty-three
feet, or from six to eight feet less than the largest "long-limbed"
dinosaur. The height of the skeleton at the hips is fifteen feet.
There is less direct evidence that the "thunder saurian" had the power
of raising its fore quarters in the air than in the case of the
"light-limbed saurian," because no bend or supporting point in the
tail has been distinctly observed.

The third type of giant dinosaur is the less completely known
"chambered saurian," the _Camarasaurus_ of Cope or _Morosaurus_ of
Marsh, an animal more quadrupedal in gait or walking more habitually
on all fours, like the great _Cetiosaurus_, or "whale saurian,"
discovered near Oxford, England. With its shorter tail and heavier
fore limbs, it is still less probable that this animal had the power
of raising the anterior part of its body from the ground. Of a related
type, perhaps, is the largest dinosaur ever found; this is the
_Brachiosaurus_, limb-bones of which were discovered in central
Colorado in 1901 and are now preserved in the Field Columbian Museum
of Chicago. Its thigh-bone is six feet eight inches in length, and its
upper arm-bone, or humerus, is even slightly longer.

_Feeding Habits of the Giant Dinosaurs._ We still have to solve one of
the most perplexing problems of fossil physiology; how did the very
small head, provided with light jaws, slender and spoon-shaped teeth
confined to the anterior region, suffice to provide food for these
monsters? I have advanced the idea that the food of _Diplodocus_
consisted of some very abundant and nutritious species of water-plant;
that the clawed feet were used in uprooting such plants, while the
delicate anterior teeth were employed only for drawing them out of the
water; that the plants were drawn down the throat in large quantities
without mastication, since there were no grinding or back teeth
whatever in this animal. Unfortunately for this theory, it is now
found that the front feet were not provided with many claws, there
being only a single claw on the inner side. Nevertheless by some such
means as this, these enormous animals could have obtained sufficient
food in the water to support their great bulk.

_The Carnivorous Dinosaurs._ Mingling with the larger bones in the
quarry are the more or less perfect remains of swamp turtles, of dwarf
crocodiles, of the entirely different group of plated dinosaurs, or
_Stegosauria_, but especially of two entirely distinct kinds of large
and small flesh-eating dinosaurs. The latter rounded out and gave
variety to the dinosaur society, and there is no doubt that they
served the savage but useful purpose, rendered familiar by the
doctrine of Malthus, of checking overpopulation. These fierce animals
had the same remote ancestry as the giant dinosaurs, but had gradually
acquired entirely different habits and appearance.

Far inferior in size, they were superior in agility, exclusively
bipedal, with very long, powerful hind limbs, upon which they advanced
by running or springing, and with short fore limbs, the exact uses of
which are difficult to ascertain. Both hands and feet were provided
with powerful tearing claws. On the hind foot is the back claw, so
characteristic of the birds, which during the Triassic period left its
faint impression almost everywhere in the famous Connecticut valley
imprints of these animals. That the fore limb and hand were of some
distinct use is proved by the enormous size of the thumb-claw; while
the hand may not have conveyed food to the mouth, it may have served
to seize and tear the prey. As to the actual pose in feeding, there
can be little doubt as to its general similarity to that of the
_Raptores_ among the birds, as suggested to me by Dr. Wortman (see
fig. 10); one of the hind feet rested on the prey, the other upon the
ground, the body being further balanced or supported by the vertebræ
of the tail. The animal was thus in a position to apply its teeth and
exert all the power of its very powerful arched back in tearing off
its food. That the gristle of the bone or cartilage was very palatable
is attested not only by the toothmarks upon these bones, but by many
similar markings found in the Bone-Cabin Quarry.

_The Bird-Catching Dinosaur._ Of all the bird-like dinosaurs which
have been discovered, none possesses greater similitude to the birds
than the gem of the quarry, the little animal about seven feet in
length which we have named _Ornitholestes_, or the "bird-catching
dinosaur." It was a marvel of speed, agility, and delicacy of
construction. Externally its bones are simple and solid-looking, but
as a matter of fact they are mere shells, the walls being hardly
thicker than paper, the entire interior of the bone having been
removed by the action of the same marvelous law of adaptation which
sculptured the vertebræ of its huge contemporaries. There is no
evidence, however, that these hollow bones were filled with air from
the lungs, as in the case of the bones of birds. The foot is
bird-like; the hand is still more so; in fact, no dinosaur hand has
ever before been found which so closely mimics that of a bird in the
great elongation of the first or index-finger, in the abbreviation of
the thumb and middle finger, and in the reduction of the ring-finger.
These fingers, with sharp claws, were not strong enough for climbing,
and the only special fitness we have been able to imagine is that they
were used for the grasping of a light and agile prey (see figs. 17,
18.)

Another reason for the venture of designating this animal as the
"bird-catcher" is that the Jurassic birds (not thus far discovered in
America, but known from the _Archæopteryx_ of Germany) were not so
active or such strong fliers as existing birds; in fact, they were not
unlike the little dinosaur itself. They were toothed, long-tailed,
short-armed, the body was feathered instead of scaled; they rose
slowly from the ground. This renders it probable that they were the
prey of the smaller pneumatic-built dinosaurs such as the present
animal.

This hypothetical bird-catcher seems to have been designed to spring
upon a delicately built prey, the structure being the very antipode of
that of the large carnivorous dinosaurs. A difficulty in the
bird-catching theory, namely, that the teeth are not as sharp as one
would expect to find them in a flesh-eater, is somewhat offset by the
similarity of the teeth to those of the bird-eating monitor lizards
(_Varanus_), which are not especially sharp.

_The Great Yield of the Quarry._ Our explorations in the quarry began
in the spring of 1898, and have continued ever since during favorable
weather. The total area explored at the close of the sixth year was
seven thousand two hundred and fifty square feet. Not one of the
twelve-foot squares into which the quarry was plotted lacked its
covering of bones, and in some cases the bones were two or three deep.
Each year we have expected to come to the end of this great deposit,
but it still yields a large return, although we have reason to believe
that we have exhausted the richest portions.

We have taken up four hundred and eighty-three parts of animals, some
of which may belong to the same individuals. These were packed in two
hundred and seventy-five boxes, representing a gross weight of nearly
one hundred thousand pounds. Reckoning from the number of thigh-bones,
we reach, as a rough estimate of the total, seventy-three animals of
the following kinds: giant herbivorous dinosaurs, 44; plated
herbivorous dinosaurs, or stegosaurs, 3; iguanodonts or smaller
herbivorous dinosaurs, 4; large carnivorous dinosaurs, 6; small
carnivorous dinosaurs, 3; crocodiles, 4; turtles, 5. But this
represents only a part of the whole deposit, which we know to be of
twice the extent already explored, and these figures do not include
the bones which were partly washed out and used in the construction
of the Bone-Cabin. The grand total would probably include parts of
over one hundred giant dinosaurs.

_The Struggle for Existence Among the Dinosaurs._ Never in the whole
history of the world as we now know it have there been such remarkable
land scenes as were presented when the reign of these titanic reptiles
was at its climax. It was also the prevailing life-picture of England,
Germany, South America, and India. We can imagine herds of these
creatures from fifty to eighty feet in length, with limbs and gait
analogous to those of gigantic elephants, but with bodies extending
through the long, flexible, and tapering necks into the diminutive
heads, and reaching back into the equally long and still more tapering
tails. The four or five varieties which existed together were each
fitted to some special mode of life; some living more exclusively on
land, others for longer periods in the water.

The competition for existence was not only with the great carnivorous
dinosaurs, but with other kinds of herbivorous dinosaurs (the
iguanodonts), which had much smaller bodies to sustain and a much
superior tooth mechanism for the taking of food.

The cutting off of this giant dinosaur dynasty was nearly if not quite
simultaneous the world over. The explanation which is deducible from
similar catastrophes to other large types of animals is that a very
large frame, with a limited and specialized set of teeth fitted only
to a certain special food, is a dangerous combination of characters.
Such a monster organism is no longer adaptable; any serious change of
conditions which would tend to eliminate the special food would also
eliminate these great animals as a necessary consequence.

  [Illustration: Fig. 46.--Badlands on the Red Deer River in
  Alberta. This region is the richest known collecting ground for
  cretacic dinosaurs.]

There is an entirely different class of explanations, however, to be
considered, which are consistent both with the continued fitness of
structure of the giant dinosaurs themselves and with the survival of
their especial food; such, for example, as the introduction of a _new
enemy_ more deadly even than the great carnivorous dinosaurs. Among
such theories the most ingenious is that of the late Professor Cope,
who suggested that some of the small, inoffensive, and inconspicuous
forms of Jurassic mammals, of the size of the shrew and the hedgehog,
contracted the habit of seeking out the nests of these dinosaurs,
gnawing through the shells of their eggs, and thus destroying the
young. The appearance, or evolution, of any egg-destroying animals,
whether reptiles or mammals, which could attack this great race at
such a defenseless point would be rapidly followed by its extinction.
We must accordingly be on the alert for all possible theories of
extinction; and these theories themselves will fall under the
universal principle of the survival of the fittest until we
approximate or actually hit upon the truth.


FOSSIL HUNTING BY BOAT IN CANADA.

_By Barnum Brown._

"How do you know where to look for fossils?" is a common question. In
general it may be answered that the surface of North America has been
pretty well explored by government surveys and scientific expeditions
and the geologic age of the larger areas determined. Most important in
determining the geologic sequence of the earth's strata are the fossil
remains of animal and plant life. A grouping of distinct species of
fossils correlated with stratigraphic characters in the rocks
determines these subdivisions. When a collection of fossils is desired
to represent a certain period, exploring parties are sent to these
known areas. Sometimes however, chance information leads up to most
important discoveries, such as resulted from the work of the past two
seasons in Alberta, Canada.

A visitor to the Museum, Mr. J.L. Wagner, while examining our mineral
collections saw the large bones in the Reptile Hall and remarked to
the Curator of Mineralogy that he had seen many similar bones near his
ranch in the Red Deer Cañon of Alberta. After talking some time an
invitation was extended to the writer to visit his home and prospect
the cañon. Accordingly in the fall of 1909 a preliminary trip was made
to the locality.

From Didsbury, a little town north of Calgary, the writer drove
eastward ninety miles to the Red Deer River through a portion of the
newly opened grain belt of Alberta, destined in the near future to
produce a large part of the world's bread. Near the railroad the land
is mostly under cultivation and comfortable homes and bountiful grain
fields testify to the rich nature of the soil. A few miles eastward
the brushland gives way to a level expanse of grass-covered prairie
dotted here and there by large and small lakes probably of glacial
origin. Mile after mile the road follows section lines and one is
rarely out of sight of the house of some "homesteader." It is through
this level farm land that the Red Deer River wends its way flowing
through a cañon far below the surface. Near Wagner's ranch the cañon
was prospected and so many bones found that it appeared most
desirable to do extended searching along the river.

Usually fossils are found in "bad lands," where extensive areas are
denuded of grass and the surface eroded into hills and ravines. A camp
is located near some spring or stream and collectors ride or walk over
miles of these exposures in each direction till the region is
thoroughly explored. Quite different are conditions on the Red Deer
River. Cutting through the prairie land the river had formed a cañon
two to five hundred feet deep and rarely more than a mile wide at the
top. In places the walls are nearly perpendicular and the river winds
in its narrow valley, touching one side then crossing to the other so
that it is impossible to follow up or down its course any great
distance even on horseback.

It was evident that the most feasible way to work these banks was from
a boat; consequently in the summer of 1910 our party proceeded to the
town of Red Deer, where the Calgary-Edmonton railroad crosses the
river. There a flatboat, twelve by thirty feet in dimension, was
constructed on lines similar to a western ferry boat, having a
carrying capacity of eight tons with a twenty-two foot oar at each end
to direct its course. The rapid current averaging about four miles per
hour precluded any thought of going up stream in a large boat, so it
was constructed on lines sufficiently generous to form a living boat
as well as to carry the season's collection of fossils.

Supplied with a season's provisions, lumber for boxes, and plaster for
encasing bones, we began our fossil cruise down a cañon which once
echoed songs of the _Bois brulé_, for this was at one time the fur
territory of the great Hudson Bay Company.

  [Illustration: Fig. 47.--American Museum Expedition on the Red
  Deer River. Fossils secured along the banks were packed and loaded
  aboard the large scow and floated down the river to the railway
  station.]

No more interesting or instructive journey has ever been taken by the
writer. High up on the plateau, buildings and haystacks proclaim a
well-settled country, but habitations are rarely seen from the river
and for miles we floated through picturesque solitude unbroken save by
the roar of the rapids.

Especially characteristic of this cañon are the slides where the
current setting against the bank has undermined it until a mountain of
earth slips into the river, in some cases almost choking its course.
A continual sorting thus goes on, the finer material being carried
away while the boulders are left as barriers forming slow moving
reaches of calm water and stretches of rapids difficult to navigate
during low water. In one of these slides we found several small mammal
jaws and teeth not known before from Canada, associated with fossil
clam shells of Eocene age.

The long midsummer days in latitude 52° gave many working hours, but
with frequent stops to prospect the banks we rarely floated more than
twenty miles per day. An occasional flock of ducks and geese were
disturbed as our boat approached and bank beaver houses were
frequently passed, but few of the animals were seen during the
daytime. Tying the boat to a tree at night we would go ashore to camp
among the trees where after dinner pipes were smoked in the glow of a
great camp fire. Only a fossil hunter or a desert traveler can fully
appreciate the luxury of abundant wood and running water. In the
stillness of the night the underworld was alive and many little feet
rustled the leaves where daylight disclosed no sound. Then the beaver
and muskrat swam up to investigate this new intruder, while from the
tree-tops came the constant query, "Who! Who!"

For seventy miles the country is thickly wooded with pine and poplar,
the stately spruce trees silhouetted against the sky adding a charm to
the ever changing scene. Nature has also been kind to the treeless
regions beyond, for underneath the fertile prairie, veins of good
lignite coal of varying thickness are successively cut by the river.
In many places these are worked in the river banks during winter. One
vein of excellent quality is eighteen feet thick, although usually
they are much thinner. The government right has been taken to mine
most of this coal outcropping along the river.

  [Illustration: Fig. 48.--Locality of Ankylosaurus skull in
  Edmonton formation in Red Deer River. The skull is in the rock
  just above the pick, about the center of the photograph.]

Along the upper portion of the stream are banks of Eocene age, from
which shells and mammal jaws were secured, but near the town of
Content where the river bends southward, a new series of rocks
appeared and in these our search was rewarded by finding dinosaur
bones similar to those seen at Wagner's ranch. Specimens were found in
increasing numbers as we continued our journey, and progress down the
river was necessarily much slower. Frequently the boat would be tied
up a week or more at one camp while we searched the banks, examining
the cliffs layer by layer that no fossil might escape observation.
With the little dingey the opposite side of the river was reached so
that both sides were covered at the same time from one camp. As soon
as a mile or more had been prospected or a new specimen secured, the
boat was dropped down to a new convenient anchorage. Box after box was
added to the collection till scarcely a cubit's space remained
unoccupied on board our fossil ark.

Where prairie badlands are eroded in innumerable buttes and ravines it
is always doubtful if one has seen all exposures, so there was
peculiar satisfaction in making a thorough search of these river banks
knowing that few if any fossils had escaped observation. On account of
the heavy rainfall and frequent sliding of banks new fossils are
exposed every season so that in a few years these same banks can again
be explored profitably. This river will become as classic hunting
ground for reptile remains as the Badlands of South Dakota are for
mammals.

Although the summer days are long in this latitude the season is short
and thousands of geese flying southward foretell the early winter.
Where the temperature is not infrequently forty to sixty degrees below
zero in winter, it is difficult to think of a time when a warm
climate could have prevailed, yet such condition is indicated by the
fossil plants.

When the weather became too cold to work with plaster, the fossils
were shipped from a branch railroad forty-five miles distant, the camp
material was stored for the winter and with block and tackle the big
boat was hauled up on shore above the reach of high water.

In the summer of 1911 the boat was recalked and again launched when we
continued our search from the point at which work closed the previous
year. During the summer we were visited by the Museum's President,
Prof. Henry Fairfield Osborn, and one of the Trustees, Mr. Madison
Grant. A canoeing trip, one of great interest and pleasure, was taken
with our visitors covering two hundred and fifty miles down the river
from the town of Red Deer, during which valuable material was added to
the collection and important geological data secured.

As a result of the Canadian work the Museum is enriched by a
magnificent collection of Cretaceous fossils some of which are new to
science.

FOOTNOTES:

[Footnote 19: Transactions Kansas Academy of Science, p. 43.]

[Footnote 20: From Fossil Wonders of the West. Century Magazine 1904,
vol. lxviii, pp. 680-694. Reprinted by permission.]

[Footnote 21: At this time the Union Pacific Railroad directly passed
the bluffs; in the recent improvement of the grade the main line has
been moved to the south.--H.F.O.]

[Footnote 22: A different interpretation of this contraction is given
upon p. 68.]



REFERENCES.


The published literature on this subject consists chiefly of technical
descriptions and researches scattered through the files of numerous
scientific journals in Europe and America. Only the more important
titles are cited in this list. I have also listed the recently
published text books which give the most authoritative treatment of
the dinosaurs, and two or three popular books dealing with fossil
vertebrates. Students consulting these authorities should remember
that great additions to scientific knowledge of dinosaurs have been
made during the last two decades, and much of the new evidence is as
yet unpublished or undigested. The views and conclusions presented in
this handbook are based upon the study of the American Museum
collections as well as upon the authorities cited below.


  ABEL, OTHENIUS, 1912. _Palaeobiologie der Wirbelthiere._
      Schweitzer-bart'sche Verlagsbuchh., Stuttgart.

  BRANCA U. JANENSCH, 1914. _Wissenschaftliche Ergebnisse der
      Tendaguru Expedition._ Archiv. f. Biontologie, iii Bd, i Heft.

  BROWN, BARNUM, 1902-1914. Articles in Bulletin of Amer. Mus. Nat.
      Hist., descriptive of new Cretaceous Dinosaurs.

  CHAMBERLIN & SALISBURY, 1905-7. _Geology_, vol. i-iii. (Henry Holt &
      Co. pub.)

  COPE, E.D., 1868-1895. Articles in Hayden Survey Reports, American
      Naturalist, Proceedings and Transactions of American
      Philosophical Society and elsewhere, descriptive of various new
      or little known dinosaurs.

  DOLLO, L., _Sauriens de Bernissart_, etc. Numerous articles chiefly
      in Bulletin Museum Royale Hist. Nat. Belg.

  GILMORE, C.W., 1914. _Osteology of the Armored Dinosauria in the
      U.S. National Museum with Special Reference to the Genus
      Stegosaurus._ U.S. National Museum, Bulletin No. 89, pp. 1-136,
      pll. i-xxxvii.

  GILMORE, C.W., 1909. _Osteology of the Jurassic Reptile
      Camptosaurus_ etc. Proc. U.S. Nat. Mus., vol. xxxvi, pp.
      197-332, pl. vi-xx.

  HATCHER, J.B., 1901. _Diplodocus (Marsh) its Osteology_, etc.
      Memoirs of the Carnegie Museum, vol. i, pp. 1-63, pll. i-xiii.

  HATCHER, J.B., 1903. _Osteology of Haplocanthosaurus._ Mem. Carn.
      Mus., vol. ii, pp. 1-75, pll. i-vi.

  HATCHER, MARSH & LULL, 1907. _The Ceratopsia._ U.S. Geol. Survey
      Monographs, vol. xlix, pp. i-xxx and 1-300, pll. i-li.

  HAY, O.P., 1902. _Bibliography of North American Fossil Vertebrata._
      U.S. Geol. Sur. Bull. No. 179, pp. 1-868.

  HENNIG, E., 1912. _Am Tendaguru._

  HOLLAND, W.J., 1906. _Osteology of Diplodocus._ Mem. Carn. Mus.,
      vol. ii, pp. 225-264, pl. xxiii-xxx.

  HUENE, F. VON, 1905-6. _Ueber die Dinosaurier der aussereuropäischen
      Trias._ Koken's Geol. u. Pal. Abh. N. F., B'd. viii, s. 99-154.

  HUENE, F. VON, 1907-8. _Die Dinosaurier der Europäischen
      Triasformation._ Geol. u. Pal. Abh. Supplem. Bd. pll. i-cxi.

  HUENE, F. VON, 1914. _Beiträge zur Geschichte der Archosaurier._
      Geol. u. Pal. Abh. N. F., B'd. xiii, pp. 1-53, pll. i-vii.

  HUENE, F. VON, 1903-1914. Numerous minor contributions in Anatom.
      Anzeig. Neues Jahrb. f. min., Geol. Centralbl. and other
      scientific journals.

  HUTCHINSON, REV. F.N., 1910. _Extinct Monsters and Creatures of
      Other Days._ Chapman & Hall, London.

  HUXLEY, T.H., 1859-1870. Articles, chiefly in Quarterly Journal
      Geol. Soc. and Geol. Magazine. Discussing the osteology and
      systematic relationships of various Dinosaurs.

  JAEKEL, O., 1913-14. _Ueber die Wirbelthiere in den oberen Trias von
      Halberstadt._ Palæont. Zeitschr. B'd. i, s. 155-215, taf.
      iii-iv.

  KNIPE, H.R., 1912. _Evolution in the Past._ Herbert & Daniel,
      London.

  LAMBE, LAWRENCE, 1902, with H.F. Osborn. See Osborn & Lambe.

  LAMBE, LAWRENCE, 1913-4. Articles in Ottawa Naturalist descriptive
      of new Cretacic Dinosaurs.

  LUCAS, F.A., 1901. _Extinct Animals._ Republished by the American
      Museum, Price 35c.

  LUCAS, F.A., 1901. The Restoration of Extinct Animals, Smithsonian
      Report for 1900, pp. 479-492, pll. i-viii.

  LULL, R.S., 1904. _Fossil Footprints of the Jura-Trias._ Mem. Boston
      Soc. Nat. Hist., vol. v, pp. 461-558.

  LULL, R.S., 1910. _Dinosaurian Distribution._ Am. Journ. Sci., vol.
      xxix, pp. 1-39; _The Armor of Stegosaurus_, ibid., pp. 201-210;
      _Stegosaurus ungulatus_, ibid., vol. xxx, pp. 361-377.

  MARSH, O.C., 1877-1896. Numerous articles in the American Journal of
      Science descriptive of new Dinosaurs or announcing results of
      his studies on these fossils.

  MARSH, O.C., 1896. _The Dinosaurs of North America._ U.S. Geol.
      Survey, 16th Ann. Rep., pt. i, pp. 133-414, pll. i-lxxxv.

  NOPSCA, 1899, 1902, 1904. _Dinosaurierreste aus Siebenburgen
      (Telmatosaurus, etc._). Denkschr. math.-naturwiss. Kl. Kais.
      Akad. Wiss. Wien, b'd. lxviii, lxxii, lxxiv.

  NOPSCA, 1906. _Zur Kenntniss der Genus Streptospondylus._ Beit. zur
      Pal. Oest-ung. Bd. xix.

  NOPSCA, F., 1902-1911. Various articles on European Dinosaurs in
      Geological Magazine, Bull. Soc. Geol. Norm., etc.

  OSBORN, H.F., 1899. _A Skeleton of Diplodocus_, Mem. Am. Mus. Nat.
      Hist., vol. i, pp. 191-214, pll. xxiv-xxviii.

  OSBORN, H.F., 1912. _Crania of Tyrannosaurus and Allosaurus;
      Integument of the Iguanodont Dinosaur Trachodon_, Mem. Am. Mus.
      Nat. Hist., N. S., vol. i, pp. 1-54, pll. i-x.

  OSBORN, H.F., 1898-1914. Articles in American Museum Bulletin,
      descriptive of Sauropoda, _Ornitholestes_, _Allosaurus_,
      _Tyrannosaurus_.

  OSBORN & LAMBE, 1902. _Vertebrata of the Mid-Cretaceous of the
      North-West Territory._ Can. Geol. Survey Publications Quarto
      series, vol. iii.

  OWEN, R., 1853-1877. Monographs on Fossil Reptilia.
      Palæontographical Society, London.

  RIGGS, E.S., 1901-4. Articles on Sauropoda in Field Museum of Nat.
      Hist. Publications, Geology.

  SCHUCHERT, CHAS., 1910. _Palæogeography of North America._ Bull.
      Geol. Soc. Am., vol. xx, pp. 427-606, pll. 46-101.

  STRÖMER VON REICHENBACH, E., 1912. _Lehrbuch der Palæontologie, ii,
      Wirbelthiere_ (B.G. Teubner, Leipzig u. Berlin.)

  THÉVENIN, A., 1907. _Paleontologie de Madagascar, iv, Dinosaurs._
      Ann. de Paléont, t. ii, pp. 121-136, 2 pll.

  WOODWARD, A.S., 1898. _Vertebrate Palæontology._ Cambridge Science
      Manuals.

  ZITTEL (Broili u. a. rev.) 1911. _Grundzuge der Palæontologie._

  ZITTEL (EASTMAN transl.), 1902. _Textbook of Palæontology, vol. ii,
      Vertebrata_ (_except Mammals_). Macmillan & Co.



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    | Typographical errors corrected in text:                      |
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    | Page   9: Palaeontology replaced with Palæontology           |
    | Page  36: familar replaced with familiar                     |
    | Page  49: Palaeontology not replaced because it quotes       |
    |           another book.                                      |
    | Page  66: pecularity replaced with peculiarity               |
    | Page  70: nust replaced with must                            |
    | Page 129: consulation replaced with consultation             |
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