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Title: Geology and Inhabitants of the Ancient World
Author: Owen, Richard
Language: English
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[Illustration: GEOLOGY AND INHABITANTS OF THE ANCIENT WORLD.
THE EXTINCT ANIMALS RESTORED BY B. WATERHOUSE HAWKINS. F.G.S. F.L.S.
PUBLISHED FOR THE CRYSTAL PALACE LIBRARY, BY BRADBURY & EVANS, 11,
BOUVERIE ST.
MACLURE & CO. LITH. TO THE QUEEN.]
GEOLOGY AND INHABITANTS
OF THE
ANCIENT WORLD.
DESCRIBED BY
RICHARD OWEN, F.R.S.
THE ANIMALS CONSTRUCTED BY B. W. HAWKINS, F.G.S.
CRYSTAL PALACE LIBRARY,
AND
BRADBURY & EVANS, 11, BOUVERIE STREET, LONDON.
1854.
BRADBURY AND EVANS,
PRINTERS TO THE CRYSTAL PALACE COMPANY,
WHITEFRIARS.
CONTENTS.
PAGE
INTRODUCTION 5
THE SECONDARY ISLAND 7
CHALK FORMATION 9
THE MOSASAURUS 10
THE PTERODACTYLE 11
WEALDEN FORMATION 14
THE IGUANODON 14
THE HYLÆOSAURUS 17
OOLITE FORMATION 19
THE MEGALOSAURUS 19
PTERODACTYLES OF THE OOLITE 22
TELEOSAURUS 22
LIAS FORMATION 25
ENALIOSAURIA 25
THE ICHTHYOSAURUS 25
ICHTHYOSAURUS PLATYODON 29
ICHTHYOSAURUS TENUIROSTRIS 30
ICHTHYOSAURUS COMMUNIS 30
PLESIOSAURUS 31
PLESIOSAURUS MACROCEPHALUS 31
PLESIOSAURUS DOLICHODEIRUS 32
PLESIOSAURUS HAWKINSII 33
NEW RED SANDSTONE 35
BATRACHIA 35
LABYRINTHODON SALAMANDROIDES 36
LABYRINTHODON PACHYGNATHUS 38
DICYNODON 38
[Illustration: {uncaptioned}]
GEOLOGY AND INHABITANTS OF THE ANCIENT WORLD.
INTRODUCTION.
Before entering upon a description of the restorations of the Extinct
Animals, placed on the Geological Islands in the great Lake, a brief
account may be premised of the principles and procedures adopted in
carrying out this attempt to present a view of part of the animal
creation of former periods in the earth’s history.
Those extinct animals were first selected of which the entire, or nearly
entire, skeleton had been exhumed in a fossil state. To accurate
drawings of these skeletons an outline of the form of the entire animal
was added, according to the proportions and relations of the skin and
adjacent soft parts to the superficial parts of the skeleton, as yielded
by those parts in the nearest allied living animals. From such an
outline of the exterior, Mr. Waterhouse Hawkins prepared at once a
miniature model form in clay.
This model was rigorously tested in regard to all its proportions with
those exhibited by the bones and joints of the skeleton of the fossil
animal, and the required alterations and modifications were successively
made, after repeated examinations and comparisons, until the result
proved satisfactory.
The next step was to make a copy in clay of the proof model, of the
natural size of the extinct animal: the largest known fossil bone, or
part, of such animal being taken as the standard according to which the
proportions of the rest of the body were calculated agreeably with those
of the best preserved and most perfect skeleton. The model of the full
size of the extinct animal having been thus prepared, and corrected by
renewed comparisons with the original fossil remains, a mould of it was
prepared, and a cast taken from this mould, in the material of which the
restorations, now exposed to view, are composed.
There are some very rare and remarkable extinct animals of which only
the fossil skull and a few detached bones of the skeleton have been
discovered: in most of these the restoration has been limited to the
head, as, for example, in the case of the Mosasaurus; and only in two
instances—those, viz., of the Labyrinthodon and Dicynodon—has Mr.
Hawkins taken upon himself the responsibility of adding the trunk to the
known characters of the head, such addition having been made to
illustrate the general affinities and nature of the fossil, and the kind
of limbs required to produce the impressions of the footprints, where
these have been detected and preserved in the petrified sands of the
ancient sea-shores trodden by these strange forms of the Reptilian
class.
With regard to the hair, the scales, the scutes, and other modifications
of the skin, in some instances the analogy of the nearest allied living
forms of animals has been the only guide; in a few instances, as in that
of the Ichthyosaurus, portions of the petrified integument have been
fortunately preserved, and have guided the artist most satisfactorily in
the restoration of the skin and soft parts of the fins; in the case of
other reptiles, the bony plates, spines, and scutes have been discovered
in a fossil state, and have been scrupulously copied in the attempt to
restore the peculiar tegumentary features of the extinct reptiles, as
_e.g._ in the Hylæosaurus.
In every stage of this difficult, and by some it may be thought,
perhaps, too bold, attempt to reproduce and present to human gaze and
contemplation the forms of animal life that have successively flourished
during former geological phases of time, and have passed away long ages
prior to the creation of man, the writer of the following brief notice
of the nature and affinities of the animals so restored feels it a duty,
as it is a high gratification to him, to testify to the intelligence,
zeal, and peculiar artistic skill by which his ideas and suggestions
have been realised and carried out by the talented director of the
fossil department, Mr. Waterhouse Hawkins. Without the combination of
science, art, and manual skill, happily combined in that gentleman, the
present department of the Instructive Illustrations at the Crystal
Palace could not have been realised.
The Secondary Island.
The most cursory observation of the surface of the earth shows that it
is composed of distinct substances, such as clay, chalk, lias,
limestone, coal, slate, sandstone, &c.; and a study of such substances,
their relative position and contents, has led to the conviction that
these external parts of the earth have acquired their present condition
gradually, under a variety of circumstances, and at successive periods,
during which many races of animated beings, distinct both from those of
other periods and from those now living, have successively peopled the
land and the waters; the remains of these creatures being found buried
in many of the layers or masses of mineral substances, forming the crust
of the earth.
The object of the Islands in the Geological Lake is to demonstrate the
order of succession, or superposition, of these layers or strata, and to
exhibit, restored in form and bulk, as when they lived, the most
remarkable and characteristic of the extinct animals and plants of each
stratum.
The series of mineral substances and strata represented in the smaller
island have been called by geologists “secondary formations,” because
they lie between an older series termed “primary,” and a newer series
termed “tertiary:” the term “formation” meaning any assemblage of rocks
or layers which have some character in common, whether of origin, age,
or composition.[1]
Following the secondary formations as they descend in the earth, or
succeed each other from above downwards, and as they are shown,
obliquely tilted up out of their original level position from left to
right, in the Secondary Island, they consist: 1st, of the Chalk or
Cretaceous group; 2nd, the Wealden; 3rd, the Oolite; 4th, the Lias; and
5th, the New Red Sandstone.
THE CHALK.
The chalk formations or “cretaceous group of beds” include strata of
various mineral substances; but the white chalk which forms the cliffs
of Dover and the adjoining coasts, and the downs and chalk quarries of
the South of England, is the chief and most characteristic formation.
Chalk, immense as are the masses in which it has been deposited, owes
its origin to living actions; every particle of it once circulated in
the blood or vital juices of certain species of animals, or of a few
plants, that lived in the seas of the secondary period of geological
time. White chalk consists of carbonate of lime, and is the result of
the decomposition chiefly of coral-animals (_Madrepores_, _Millepores_,
_Flustra_, _Cellepora_, &c.), of sea-urchins (_Echini_), and of
shell-fishes (_Testacea_), and of the mechanical reduction, pounding,
and grinding of their shells. Such chalk-forming beings still exist, and
continue their operations in various parts of the ocean, especially in
the construction of coral reefs and islands.
Every river that traverses a limestone district carries into the sea a
certain proportion of caustic lime in solution: the ill effects of the
accumulation of this mineral are neutralised by the power allotted to
the above-cited sea-animals to absorb the lime, combine it with
carbonic-acid, and precipitate or deposit it in the condition of
insoluble chalk, or carbonate of lime.
The entire cretaceous series includes from above downwards:
Maestricht beds of yellowish chalk.
Upper white chalk with flints.
Lower white chalk without flints.
Upper green-sand.
Gault.
Lower green-sand and Kentish rag.
The best known and most characteristic large extinct animal of the chalk
formations is chiefly found in the uppermost and most recent division,
and is called
No. 1.—The Mosasaurus.
(_Mosasaurus Hoffmanni_, Hoffmann’s Mosasaur.)
Of this animal almost the entire skull has been discovered, but not
sufficient of the rest of the skeleton to guide to a complete
restoration of the animal. The head only, therefore, is shown, of the
natural size, at the left extremity of the Secondary Island.
The first or generic name of this animal is derived from the locality,
Maestricht, on the river Meuse (Lat. _Mosa_), in Germany, where its
remains have been chiefly discovered, and from the Greek word _sauros_,
a lizard, to which tribe of animals it belongs. Its second name refers
to its discoverer, Dr. Hoffmann, of Maestricht, surgeon to the forces
quartered in that town in 1780. This gentleman had occupied his leisure
by the collection of the fossils from the quarries which were then
worked to a great extent at Maestricht for a kind of yellowish stone of
a chalky nature, and belonging to the most recent of the secondary class
of formations in geology. In one of the great subterraneous quarries or
galleries, about five hundred paces from the entrance, and ninety feet
below the surface, the quarrymen exposed part of the skull of the
Mosasaurus, in a block of stone which they were engaged in detaching. On
this discovery they suspended their work, and went to inform Dr.
Hoffmann, who, on arriving at the spot, directed the operations of the
men, so that they worked out the block without injury to the fossil; and
the doctor then, with his own hands, cleared away the matrix and exposed
the jaws and teeth, casts of which are shown in the cretaceous rock of
the Island.
This fine specimen, which Hoffmann had added with so much pains and care
to his collection, soon, however, became a source of chagrin to him. One
of the canons of the cathedral at Maestricht, who owned the surface of
the soil beneath which was the quarry whence the fossil had been
obtained, when the fame of the specimen reached him, pleaded certain
feudal rights to it. Hoffmann resisted, and the canon went to law. The
Chapter supported the canon, and the decree ultimately went against the
poor surgeon, who lost both his specimen and his money—being made to pay
the costs of the action. The canon did not, however, long enjoy
possession of the unique specimen. When the French army bombarded
Maestricht in 1795, directions were given to spare the suburb in which
the famous fossil was known to be preserved; and after the capitulation
of the town it was seized and borne off in triumph. The specimen has
since remained in the museum of the Garden of Plants at Paris.
This skull of the Mosasaurus measures four and a half feet long and two
and a half feet wide. The large pointed teeth on the jaws are very
conspicuous; but, in addition to these, the gigantic reptile had teeth
on a bone of the roof of the mouth (the pterygoid), like some of the
modern lizards. The entire length of the animal has been estimated at
about thirty feet. It is conjectured to have been able to swim well, and
to have frequented the sea in quest of prey: its dentition shows its
predatory and carnivorous character, and its remains have hitherto been
met with exclusively in the chalk formations. Besides the specimens from
St. Peter’s Mount, Maestricht, of which the above-described skull is the
most remarkable, fossil bones and teeth of the Mosasaurus have been
found in the chalk of Kent, and in the green-sand—a member of the
cretaceous series—in New Jersey, United States of America. No animal
like the Mosasaurus is now known to exist.
Nos. 2 & 3.—The Pterodactyle.
Nos. 2 and 3 are restorations of a flying reptile or dragon, called
Pterodactyle, from the Greek words _pteron_, a wing, and _dactylos_, a
finger; because the wings are mainly supported by the outer finger,
enormously lengthened and of proportionate strength, which,
nevertheless, answers to the little finger of the human hand. The wings
consisted of folds of skin, like the leather wings of the bat; and the
Pterodactyles were covered with scales, not with feathers: the head,
though somewhat resembling in shape that of a bird, and supported on a
long and slender neck, was provided with long jaws, armed with teeth;
and altogether the structure of these extinct members of the reptilian
class is such as to rank them amongst the most extraordinary of all the
creatures yet discovered in the ruins of the ancient earth.
Remains of the Pterodactyle were first discovered, in 1784, by Prof.
Collini, in the lithographic slate of Aichstadt, in Germany, which slate
is a member of the oolitic formations: the species so discovered was at
first mistaken for a bird, and afterwards supposed to be a large kind of
bat, but had its true reptilian nature demonstrated by Baron Cuvier, by
whom it was called the _Pterodactylus longirostris_, or Long-beaked
Pterodactyle: it was about the size of a curlew.
A somewhat larger species—the _Pterodactylus macronyx_, or Long-clawed
Pterodactyle—was subsequently discovered by the Rev. Dr. Buckland, in
the lias formation of Lyme Regis: its wings, when expanded, must have
been about four feet from tip to tip. The smallest known species—the
_Pterodactylus brevirostris_, or Short-beaked Pterodactyle—was
discovered in the lithographic slate at Solenhofen, Germany, and has
been described by Professor Soemmering.
Remains of the largest known kinds of Pterodactyle have been discovered
more recently in chalk-pits, at Burham, in Kent. The skull of one of
these species—the _Pterodactylus Cuvieri_—was about twenty inches in
length, and the animal was upborne on an expanse of wing of probably not
less than eighteen feet from tip to tip. The restored specimen of this
species is numbered 3.
A second very large kind of Pterodactyle—the _Pterodactylus
compressirostris_, or Thin-beaked Pterodactyle—had a head from fourteen
to sixteen inches in length, and an expanse of wing, from tip to tip, of
fifteen feet. The remains of this species have also been found in the
chalk of Kent. From the same formation and locality a third large kind
of Pterodactyle, although inferior in size to the two foregoing, has
been discovered, called the _Pterodactylus conirostris_, and also—until
the foregoing larger kinds were discovered—_Pterodactylus giganteus_.
The long, sharp, conical teeth in the jaws of the Pterodactyles indicate
them to have preyed upon other living animals; their eyes were large, as
if to enable them to fly by night. From their wings projected fingers,
terminated by long curved claws, and forming a powerful paw, wherewith
the animal was enabled to creep and climb, or suspend itself from trees.
It is probable, also, that the Pterodactyles had the power of swimming;
some kinds, _e.g._, the _Pterodactylus Gemmingi_, had a long and stiff
tail. “Thus,” writes Dr. Buckland, “like Milton’s Fiend, all qualified
for all services and all elements, the creature was a fit companion for
the kindred reptiles that swarmed in the seas, or crawled on the shores
of a turbulent planet.
‘The Fiend,
O’er bog, or steep, through strait, rough, dense, or rare,
With head, hands, wings, or feet, pursues his way,
And swims, or sinks, or wades, or creeps, or flies.’
_Paradise Lost_, Book II.”
THE WEALDEN.
The Wealden is a mass of petrified clay, sand, and sandstone, deposited
from the fresh or brackish water of probably some great estuary, and
extending over parts of the counties of Kent, Surrey, and Sussex. This
fresh-water formation derives its name from the “Weald” or “Wold” of
Kent, where it was first geologically studied, and where it is exposed
by the removal of the chalk, which covers or overlies it, in other parts
of the South of England.
The Wealden is divided into three groups of strata, which succeed each
other in the following descending order:—
1st. Weald Clay, sometimes including thin beds of sand and shelly
limestone, forming beds of from 140 to 280 feet in depth or vertical
thickness.
2nd. Hastings Sand, in which occur some clays and calcareous grits,
forming beds of from 400 to 500 feet in depth.
3rd. Purbeck Beds, so called from being exposed chiefly in the Isle of
Purbeck, off the coast of Dorsetshire, where it forms the quarries of
the limestone for which Purbeck is famous: the beds of limestones and
marls are from 150 to 200 feet in depth.
Nos. 4 & 5.—The Iguanodon.
(_Iguanodon Mantelli_, Conybeare.)
One afternoon, in the spring of 1822, an accomplished lady, the wife of
a medical practitioner, at Lewes, in Sussex, walking along the
picturesque paths of Tilgate Forest, discovered some objects in the
coarse conglomerate rock of the quarries of that locality, which, from
their peculiar form and substance, she thought would be interesting to
her husband, whose attention had been directed, during his professional
drives, to the geology and fossils of his neighbourhood.
The lady was Mrs. Mantell: her husband, the subsequently distinguished
geologist, Dr. Mantell,[2] perceived that the fossils discovered by his
wife were teeth, and teeth of a large and unknown animal.
“As these teeth,” writes the doctor, “were distinct from any that had
previously come under my notice, I felt anxious to submit them to the
examination of persons whose knowledge and means of observation were
more extensive than my own. I therefore transmitted specimens to some of
the most eminent naturalists in this country and on the continent. But
although my communications were acknowledged with that candour and
liberality which constantly characterise the intercourse of scientific
men, yet no light was thrown upon the subject, except by the illustrious
Baron Cuvier, whose opinions will best appear by the following extract
from the correspondence with which he honoured me:—
“‘These teeth are certainly unknown to me; they are not from a
carnivorous animal, and yet I believe that they belong, from their
slight degree of complexity, the notching of their margins, and the thin
coat of enamel that covers them, to the order of reptiles.
“‘May we not here have a new animal!—a herbivorous reptile? And, just as
at the present time with regard to mammals (land-quadrupeds with warm
blood), it is amongst the herbivorous that we find the largest species,
so also with the reptiles at the remote period when they were the sole
terrestrial animals, might not the largest amongst them have been
nourished by vegetables?
“‘Some of the great bones which you possess may belong to this animal,
which, up to the present time, is unique in its kind. Time will confirm
or confute this idea, since it is impossible but that one day a part of
the skeleton, united to portions of jaws with the teeth, will be
discovered.’”
“These remarks,” Dr. Mantell proceeds to say, “induced me to pursue my
investigations with increased assiduity, but hitherto they have not been
attended with the desired success, no connected portion of the skeleton
having been discovered. Among the specimens lately connected, some,
however, were so perfect, that I resolved to avail myself of the
obliging offer of Mr. Clift (to whose kindness and liberality I hold
myself particularly indebted), to assist me in comparing the fossil
teeth with those of the recent Lacertæ in the Museum of the Royal
College of Surgeons. The result of this examination proved highly
satisfactory, for in an Iguana which Mr. Stutchbury had prepared to
present to the College, we discovered teeth possessing the form and
structure of the fossil specimens.” (Phil. Trans., 1825, p. 180.) And he
afterwards adds:—“The name Iguanodon, derived from the form of the
teeth, (and which I have adopted at the suggestion of the Rev. W.
Conybeare,) will not, it is presumed, be deemed objectionable.” (Ib. p.
184.)
The further discovery which Baron Cuvier’s prophetic glance saw buried
in the womb of time, and the birth of which verified his conjecture that
some of the great bones collected by Dr. Mantell belonged to the same
animal as the teeth, was made by Mr. W. H. Bensted, of Maidstone, the
proprietor of a stone-quarry of the Shanklin-sand formation, in the
close vicinity of that town. This gentleman had his attention one day,
in May, 1834, called by his workmen to what they supposed to be
petrified wood in some pieces of stone which they had been blasting. He
perceived that what they supposed to be wood was fossil bone, and with a
zeal and care which have always characterised his endeavours to secure
for science any evidence of fossil remains in his quarry, he immediately
resorted to the spot. He found that the bore or blast by which these
remains were brought to light, had been inserted into the centre of the
specimen, so that the mass of stone containing it had been shattered
into many pieces, some of which were blown into the adjoining fields.
All these pieces he had carefully collected, and proceeding with equal
ardour and success to the removal of the matrix from the fossils, he
succeeded after a month’s labour in exposing them to view, and in
fitting the fragments to their proper places.
This specimen is now in the British Museum.
Many other specimens of detached bones, including vertebræ or parts of
the back-bone, especially that part resting on the hind limbs, and
called the “pelvis,” bones of the limbs, down to those that supported
the claws, together with jaws and teeth, which have since been
successively discovered, have enabled anatomists to reconstruct the
extinct Iguanodon, and have proved it to have been a herbivorous
reptile, of colossal dimensions, analogous to the diminutive Iguana in
the form of its teeth, but belonging to a distinct and higher order of
reptiles, more akin to the crocodiles. The same rich materials,
selecting the largest of the bones as a standard, have served for the
present restorations (Nos. 4 and 5) of the animal, as when alive: all
the parts being kept in just proportion to the standard bones, and the
whole being thus brought to the following dimensions:—
Total length, from the nose or muzzle 34 feet 9 inches.
to the end of the tail
Greatest girth of the trunk 20 ” 5 ”
Length of the head 3 ” 6 ”
Length of the tail 15 ” 6 ”
The character of the scales is conjectural, and the horn more than
doubtful, though attributed to the Iguanodon by Dr. Mantell and most
geologists.
This animal probably lived near estuaries and rivers, and may have
derived its food from the _Clathrariæ_, _Zamiæ_, _Cycades_, and other
extinct trees, of which the fossil remains abound in the same formations
as those yielding the bones and teeth of the Iguanodon.
These formations are the Wealden and the Neocomian or green-sand: the
localities in which the remains of the Iguanodon have been principally
found, are the Weald of Kent and Sussex: Horsham, in Sussex; Maidstone,
in Kent; and the Isle of Wight.
Restorations of the _Cycas_ and _Zamia_ are placed, with the Iguanodon,
on the Wealden division of the Secondary Island.
No. 6.—The Hylæosaurus. (_Hylæosaurus Owenii._)
The animal, so called by its discoverer, Dr. Mantell, belongs to the
same highly organised order of the class of reptiles as the Iguanodon,
that, viz., which was characterised by a longer and stronger sacrum and
pelvis, and by larger limbs than the reptiles of the present day
possess; they were accordingly better fitted for progression on dry
land, and probably carried their body higher and more freely above the
surface of the ground.
Visiting, in the summer of 1832, a quarry in Tilgate Forest, Dr. Mantell
had his attention attracted to some fragments of a large mass of stone,
which had recently been broken up, and which exhibited traces of
numerous pieces of bone. The portions of the rock, which admitted of
being restored together, were cemented, and then the rock was chiselled
from the fossil bones, which consisted of part of the back-bone or
vertebral column, some ribs, the shoulder bones called scapula and
coracoid, and numerous long angular bones or spines which seemed to have
supported a lofty serrated or jagged crest, extended along the middle of
the back, as in some of the small existing lizards, _e.g._, the Iguana:
cut No. 6. Many small dermal bones were also found, which indicate the
Hylæosaurus to have been covered by hard tuberculate scales, like those
of some of the Australian lizards, called _Cyclodus_.
This character of the skin, and the serrated crest, are accurately given
in the restoration, the major part of which, however, is necessarily at
present conjectural, and carried out according to the general analogies
of the saurian form. The size is indicated with more certainty according
to the proportions of the known vertebræ and other bones.
[Illustration: No. 6. Diagram of the Slab containing the Bones of
Hylæosaurus.]
THE OOLITE.
The division of the secondary formations, called “Oolite,” takes its
name from the most characteristic of its constituents, which is a
variety of limestone composed of numerous small grains, resembling the
“roe” or eggs of a fish, whence the term, (from the Greek _oon_, an egg,
_lithos_, a stone). The oolite, however, includes a great series of beds
of marine origin, which, with an average breadth of thirty miles, extend
across England, from Yorkshire in the north-east to Dorsetshire in the
south-west.
The oolite series lies below the Wealden, and where this is wanting,
below the chalk, and consists of the following subdivisions, succeeding
each other in the descending order:—
Oolite.
Upper. Portland stone and sand.
Kimmeridge clay.
Middle. Coral rag.
Oxford clay.
Lower. Cornbrash and forest marble.
Great oolite and Stonesfield slate.
Fuller’s earth.
Inferior oolite.
Upon the portion of the island representing the oolite series, the most
conspicuous of the restored animals of that period is—
No. 7.—The Megalosaurus.
The Megalosaurus, as its name implies (compounded by its discoverer, Dr.
Buckland, from the Greek _megas_, great, and _sauros_, lizard), was a
lizard-like reptile of great size, “of which,” writes Dr. Buckland,
“although no skeleton has yet been found entire, so many perfect bones
and teeth have been discovered in the same quarries, that we are nearly
as well acquainted with the form and dimensions of the limbs as if they
had been found together in a single block of stone.”
The restoration of the animal has been accordingly effected, agreeably
with the proportions of the known parts of the skeleton, and in harmony
with the general characters of the order of reptiles to which the
Megalosaurus belonged. This order—the Dinosauria (Gr. _deinos_, terribly
great _sauros_, a lizard)—is that to which the two foregoing huge
reptiles of the Wealden series belong, viz., the Iguanodon and
Hylæosaurus, and is characterised by the modifications already
mentioned, that fitted them for more efficient progression upon dry
land. The Iguanodon represented the herbivorous section of the order,
the Hylæosaurus appears, from its teeth, to have been a mixed feeder,
but the Megalosaurus was decidedly carnivorous, and, probably, waged a
deadly war against its less destructively endowed congeners and
contemporaries.
[Illustration: No. 7. Megalosaurus.]
Baron Cuvier estimated the Megalosaurus to have been about fifty feet in
length; my own calculations, founded on more complete evidence than had
been at the Baron’s command, reduce its size to about thirty-five
feet:[3] but with the superior proportional height and capacity of
trunk, as contrasted with the largest existing crocodiles, even that
length gives a most formidable character to this extinct predatory
reptile.
As the thigh-bone (_femur_) and leg-bone (_tibia_) measure each nearly
three feet, the entire hind-leg, allowing for the cartilages of the
joints, must have attained a length of two yards: a bone of the foot
(metatarsal) thirteen inches long, indicates that part, with the toes
and claws entire, to have been at least three feet in length. The form
of the teeth shows the Megalosaurus to have been strictly carnivorous,
and viewed as instruments for providing food for so enormous a reptile,
the teeth were fearfully fitted to the destructive office for which they
were designed. They have compressed conical sharp-pointed crowns, with
cutting and finely serrated anterior and posterior edges; they appear
straight, as seen when they had just protruded from the socket, but
become bent slightly backwards in the progress of growth, and the fore
part of the crown, below the summit, becomes thick and convex.
A minute and interesting description of these teeth will be found in Dr.
Buckland’s admirable “Bridgewater Treatise” (vol. i. p. 238), from which
he concludes that the teeth of the Megalosaurus present “a combination
of contrivances analogous to those which human ingenuity has adopted in
the construction of the knife, the sabre, and the saw.” The fossils
which brought to light the former existence of this most formidable
reptile, were discovered in 1823, in the oolitic slate of Stonesfield,
near Oxford, and were described by Dr. Buckland, in the volume of the
“Geological Transactions” for the year 1824.
Remains of the Megalosaurus have since been discovered in the “Bath
oolite,” which is immediately below the Stonesfield slate, and in the
“Cornbrash,” which lies above it. Vertebræ, teeth, and some bones of the
extremities have been discovered in the Wealden of Tilgate Forest, Kent,
and in the ferruginous sand, of the same age, near Cuckfield, in Sussex.
Remains of the Megalosaurus also occur in the Purbeck limestone at
Swanage Bay, and in the oolite in the neighbourhood of Malton, in
Yorkshire.
Mr. Waterhouse Hawkins’s restoration, according to the proportions
calculated from the largest portions of fossil bones of the Megalosaurus
hitherto obtained, yields a total length of the animal, from the muzzle
to the end of the tail, of thirty-seven feet; the length of the head
being five feet, the length of the tail fifteen feet; and the greatest
girth of the body twenty-two feet six inches.
Nos. 8 & 9.—Pterodactyles of the Oolite.
To the right of the Hylæosaurus, on the rock representing the greater
oolite formation, are restorations of species of Pterodactyle
(_Pterodactylus Bucklandi_, No. 9), smaller than and distinct from those
of the chalk formations. The remains of Buckland’s Pterodactyle are
found pretty abundantly in the oolitic slate of Stonesfield, near
Oxford.
Nos. 10 & 11.—Teleosaurus.
On the shore beneath the overhanging cliff of oolitic rock are two
restorations, Nos. 10 and 11, of a large extinct kind of crocodile, to
which the long and slender-jawed crocodile of the Ganges, called
“Gaviàl” or “Gharriàl” by the Hindoos, offers the nearest resemblance at
the present day. Remains of the ancient extinct British gavials have
been found in most of the localities where the oolitic formations occur,
and very abundantly in the lias cliffs near Whitby, in Yorkshire. The
name Teleosaurus (_telos_, the end, _sauros_, a lizard), was compounded
from the Greek by Professor Geoffroy St. Hilaire, for a species of these
fossil gavials, found by him in the oolite stone at Caen, in Normandy,
and has reference to his belief that they formed one—the
earliest—extreme of the crocodilian series, as this series has been
successively developed in the course of time on our planet.
The jaws are armed with numerous long, slender, sharp-pointed, slightly
curved teeth, indicating that they preyed on fishes, and the young or
weaker individuals of co-existing reptiles. The nostril is situated more
at the end of the upper jaw than in the modern gavial: the fore-limbs
are shorter, and the hind ones longer and stronger than in the gavial,
which indicates that the Teleosaur was a better swimmer; the vertebræ or
bones of the back are united by slightly concave surfaces, not
interlocked by cup and ball joints as in the modern crocodiles, whence
it would seem that the Teleosaur lived more habitually in the water, and
less seldom moved on dry land; and, as its fossil remains have been
hitherto found only in the sedimentary deposits from the sea, it may be
inferred that it was more strictly marine than the crocodile of the
Ganges.
The first specimen of a Teleosaur that was brought to light was from the
“alum-schale” which forms one layer of the lofty lias cliffs of the
Yorkshire coast, near Whitby. A brief description, and figures, of this
incomplete fossil skeleton were published by Messrs. Wooller and
Chapman, in separate communications, in the 50th volume of the
“Philosophical Transactions,” in 1758. Captain Chapman observes, “it
seems to have been an alligator;” and Mr. Wooller thought “it resembled
in every respect the Gangetic gavial.” Thus, nearly a century ago, the
true nature of the fossil was almost rightly understood, and various
were the theories then broached to account for the occurrence of a
supposed Gangetic reptile in a petrified state in the cliffs of
Yorkshire. It has required the subsequent progress of comparative
anatomy to determine, as by the characters above defined, the essential
distinction of the Teleosaur from all known existing forms of
crocodilian reptiles.
Very abundant remains, and several species, of the extinct genus have
been subsequently discovered: but always in the oolitic and liassic
formations of the secondary series of rocks.
The oolitic group of rocks are very rich in remains of both plants and
animals: many reptiles of genera and species distinct from those here
restored have been recognised and determined by portions of the
skeleton. Extremely numerous are the remains of fishes, chiefly of an
almost extinct order (_Ganoidei_), characterised by hard, shining,
enamelled scales. But the most remarkable fossils are those which
indisputably prove the existence, during the period of the “Great” or
“Lower Oolite,” of insectivorous and marsupial mammalia—_i.e._, of
warm-blood quadrupeds, which, like the shrew or hedgehog, fed on
insects, and, like the opossum, had a pouch for the transport of the
young. The lower jaw of one of these earliest known examples of the
mammalian class, found in the Stonesfield slate, near Oxford, may be
seen at the British Museum, to which it was presented by J. W. Broderip,
Esq., F.R.S., by whom it was described in the “Zoological Journal,” vol.
iii., p. 408.
It is interesting to observe that the marsupial genera, to which the
above fossil quadruped, called _Phascolotherium_, was most nearly
allied, are now confined to New South Wales and Van Diemen’s Land; since
it is in the Australian seas that is found the _Cestracion_, a
cartilaginous fish which has teeth that are most like those fossil teeth
called _Acrodus_ and _Psammodus_, so common in the oolite. In the same
Australian seas, also, near the shore, the beautiful shell-fish called
_Trigonia_ is found living, of which genus many fossil species occur in
the Stonesfield slate. Moreover, the Araucarian pines are now abundant,
together with ferns, in Australia, as they were in Europe in the oolitic
period.
THE LIAS.
“Lias” is an English provincial name adopted in geology, and applied to
a formation of limestone, marl, and petrified clay, which forms the base
of the oolite, or immediately underlies that division of secondary
rocks. The lias has been traced throughout a great part of Europe,
forming beds of a thickness varying from 500 to 1000 feet of the
above-mentioned substances, which have been gradually deposited from a
sea of corresponding extent and direction. The lias abounds with marine
shells of extinct species, and with remains of fishes that were clad
with large and hard shining scales. Of the higher or air-breathing
animals of that period, the most characteristic were the
Enaliosauria.
The creatures called Enaliosauria or Sea-lizards (from the Greek
_enalios_, of the sea, and _sauros_, lizard), were vertebrate animals,
or had back bones, breathed the air like land quadrupeds, but were
cold-blooded, or of a low temperature, like crocodiles and other
reptiles. The proof that the Enaliosaurs respired atmospheric air
immediately, and did not breathe water by means of gills like fishes, is
afforded by the absence of the bony framework of the gill apparatus, and
by the presence, position, and structure of the air passages leading
from the nostrils, and also by the bony mechanism of the capacious chest
or thoracic-abdominal cavity: all of which characters have been
demonstrated by their fossil skeletons. With these characters the
Sea-lizards combined the presence of two pairs of limbs shaped like
fins, and adapted for swimming.
The Enaliosauria offer two principal modifications of their anatomical,
and especially their bony, structure, of which the two kinds grouped
together under the respective names of Ichthyosaurus and Plesiosaurus
are the examples.
The Ichthyosaurus.
The genus Ichthyosaurus includes many species: of which three of the
best known and most remarkable have been selected for restoration to
illustrate this most singular of the extinct forms of animal life.
The name (from the Greek _ichthys_, a fish, and _sauros_, a lizard)
indicates the closer affinity of the Ichthyosaur, as compared with the
Plesiosaur, to the class of fishes. The Ichthyosaurs are remarkable for
the shortness of the neck and the equality of the width of the back of
the head with the front of the chest, impressing the observer of the
fossil skeleton with a conviction that the ancient animal must have
resembled the whale tribe and the fishes in the absence of any
intervening constriction or “neck.”
This close approximation in the Ichthyosaurs to the form of the most
strictly aquatic back-boned (vertebrate) animals of the existing
creation is accompanied by an important modification of the surfaces
forming the joints of the back-bone, each of which surfaces is hollow,
leading to the inference that they were originally connected together by
an elastic bag, or “capsule,” filled with fluid—a structure which
prevails in the class of fishes, but not in any of the whale or porpoise
tribe, nor in any, save a few of the very lowest and most fish-like, of
the existing reptiles.
With the above modifications of the head, trunk, and limbs, in relation
to swimming, there co-exist corresponding modifications of the tail. The
bones of this part are much more numerous than in the Plesiosaurs, and
the entire tail is consequently longer; but it does not show any of
those modifications that characterise the bony support of the tail in
fishes. The numerous “caudal vertebræ” of the Ichthyosaurus gradually
decrease in size to the end of the tail, where they assume a compressed
form, or are flattened from side to side, and thus the tail instead of
being short and broad, as in fishes, is lengthened out as in crocodiles.
The very frequent occurrence of a fracture of the tail, about one fourth
of the way from its extremity, in well-preserved and entire fossil
skeletons, is owing to that proportion of the end of the tail having
supported a tail-fin. The only evidence which the fossil skeleton of a
whale would yield of the powerful horizontal tail-fin characteristic of
the living animal, is the depressed or horizontally flattened form of
the bones supporting such fin. It is inferred, therefore, from the
corresponding bones of the Ichthyosaurus being flattened from side to
side, that it possessed a tegumentary tail-fin expanded in the vertical
direction. The shape of a fin composed of such perishable material is of
course conjectural, but from analogies, not necessary here to further
enlarge upon, it was probably like, or nearly like, that which the able
artist engaged in the restoration of the entire form of the animal has
given to it. Thus, in the construction of the principal swimming-organ
of the Ichthyosaurus we may trace, as in other parts of its structure, a
combination of mammalian (beast-like), saurian (lizard-like), and
piscine (fish-like) peculiarities. In its great length and gradual
diminution we perceive its saurian character; the tegumentary nature of
the fin, unsustained by bony fin-rays, bespeaks its affinity to the same
part in the mammalian whales and porpoises; whilst its vertical position
makes it closely resemble the tail-fin of the fish.
The horizontality of the tail-fin of the whale tribe is essentially
connected with their necessities as warm-blooded animals breathing
atmospheric air; without this means of displacing a mass of water in the
vertical direction, the head of the whale could not be brought with the
required rapidity to the surface to respire; but the Ichthyosaurs, not
being warm-blooded, or quick breathers, would not need to bring their
head to the surface so frequently, or so rapidly, as the whale; and,
moreover, a compensation for the want of horizontality of their tail-fin
was provided by the addition of a pair of hind-paddles, which are not
present in the whale tribe. The vertical fin was a more efficient organ
in the rapid cleaving of the liquid element, when the Ichthyosaurs were
in pursuit of their prey, or escaping from an enemy.
That the Ichthyosaurs occasionally sought the shores, crawled on the
strand, and basked in the sunshine, may be inferred from the bony
structure connected with their fore-fins, which does not exist in any
porpoise, dolphin, grampus, or whale; and for want of which, chiefly,
those warm-blooded, air-breathing, marine animals are so helpless when
left high and dry on the sands: the structure in question in the
Ichthyosaur is a strong osseous arch, inverted and spanning across
beneath the chest from one shoulder-joint to the other; and what is most
remarkable in the structure of this “scapular” arch, as it is called,
is, that it closely resembles, in the number, shape, and disposition of
its bones, the same part in the singular aquatic mammalian quadruped of
Australia, called _Ornithorhynchus_, _Platypus_, and Duck-mole. The
Ichthyosaurs, when so visiting the shore, either for sleep, or
procreation, would lie, or crawl prostrate, or with the belly resting or
dragging on the ground.
The most extraordinary feature of the head was the enormous magnitude of
the eye; and from the quantity of light admitted by the expanded pupil
it must have possessed great powers of vision, especially in the dusk.
It is not uncommon to find in front of the orbit (cavity for the eye),
in fossil skulls, a circular series of petrified thin bony plates,
ranged round a central aperture, where the pupil of the eye was placed.
The eyes of many fishes are defended by a bony covering consisting of
two pieces; but a compound circle of overlapping plates is now found
only in the eyes of turtles, tortoises, lizards, and birds. This curious
apparatus of bony plates would aid in protecting the eyeball from the
waves of the sea when the Ichthyosaurus rose to the surface, and from
the pressure of the dense element when it dived to great depths; and
they show, writes Dr. Buckland,[4] “that the enormous eye, of which they
formed the front, was an optical instrument of varied and prodigious
power, enabling the Ichthyosaurus to descry its prey at great or little
distances, in the obscurity of night, and in the depths of the sea.”
Of no extinct reptile are the materials for a complete and exact
restoration more abundant and satisfactory than of the Ichthyosaurus;
they plainly show that its general external figure must have been that
of a huge predatory abdominal fish, with a longer tail, and a smaller
tail-fin: scale-less, moreover, and covered by a smooth, or finely
wrinkled skin analogous to that of the whale tribe.
The mouth was wide, and the jaws long, and armed with numerous pointed
teeth, indicative of a predatory and carnivorous nature in all the
species; but these differed from one another in regard to the relative
strength of the jaws, and the relative size and length of the teeth.
Masses of masticated bones and scales of extinct fishes, that lived in
the same seas and at the same period as the Ichthyosaurus, have been
found under the ribs of fossil specimens, in the situation where the
stomach of the animal was placed; smaller, harder, and more digested
masses, containing also fish-bones and scales have been found, bearing
the impression of the structure of the internal surface of the intestine
of the great predatory sea-lizard. These digested masses are called
“coprolites.”
In tracing the evidences of creative power from the earlier to the later
formations of the earth’s crust, remains of the Ichthyosaurus are first
found in the lower lias, and occur, more or less abundantly, through all
the superincumbent secondary strata up to, and inclusive of, the chalk
formations. They are most numerous in the lias and oolite, and the
largest and most characteristic species have been found in these
formations.
No. 12.—Ichthyosaurus platyodon.
This most gigantic species, so called on account of the crown of the
tooth being more flattened than in other species, and having sharp
edges, as well as a sharp point, was first discovered in the lias of
Lyme Regis, in Dorsetshire. Fossil remains now in the British Museum,
and in the museum of the Geological Society, fully bear out the
dimensions exhibited by the restoration of the animal as seen basking on
the shore between the two specimens of Long-necked Plesiosaurs. The head
of this species is relatively larger in proportion to the trunk, than in
the _Ichthyosaurus communis_ or _Ichthyosaurus tenuirostris_: the lower
jaw is remarkably massive and powerful, and projects backwards beyond
the joint, as far as it does in the crocodile. In the skull of an
individual of this species, preserved in the apartments of the
Geological Society of London, the cavity for the eye, or orbit,
measures, in its long diameter, fourteen inches. The fore and hind
paddles are large and of equal size.
The lias of the valley of Lyme Regis, Dorsetshire, is the chief
grave-yard of the _Ichthyosaurus platyodon_; but its remains are pretty
widely distributed. They have been found in the lias of Glastonbury, of
Bristol, of Scarborough and Whitby, and of Bitton, in Gloucestershire;
some vertebræ, apparently of this species, have likewise been found in
the lias at Ohmden, in Germany.
No. 13.—Ichthyosaurus tenuirostris.
Behind the _Ichthyosaurus platyodon_, is placed the restoration of the
_Ichthyosaurus tenuirostris_, or Slender-snouted Fish-lizard. The most
striking peculiarity of this species is the great length and slenderness
of the jaw-bones, which, in combination with the large eye-sockets and
flattened cranium, give to the entire skull a form which resembles that
of a gigantic snipe or woodcock, with the bill armed with teeth. These
weapons, in the present species, are relatively more numerous, smaller,
and more sharply pointed than in the foregoing, and indicate that the
_Ichthyosaurus tenuirostris_ preyed on a smaller kind of fish. The
fore-paddles are larger than the hind ones. In the museum of the
Philosophical Institution, at Bristol, there is an almost entire
skeleton of the present species which measures thirteen feet in length.
It was discovered in the lias of Lyme Regis. Portions of jaws and other
parts of the skeletons of larger individuals have been found fossil in
the lias near Bristol, at Barrow-on-Soar, in Leicestershire, and at
Stratford-on-Avon. The _Ichthyosaurus tenuirostris_ has also left its
remains in the lias formation at Boll and Amburg, in Wirtemberg,
Germany.
No. 14.—Ichthyosaurus communis.
Of this species, which was the most “common,” when first discovered in
1824, but which has since been surpassed by other species in regard to
the known number of individuals, the head is restored, as protruded from
the water, to the right of the foregoing species.
The _Ichthyosaurus communis_ is characterised by its relatively large
teeth, with expanded, deeply-grooved bases, and round conical furrowed
crowns; the upper jaw contains, on each side, from forty to fifty of
such teeth. The fore-paddles are three times larger than the hind ones.
With respect to the size which it attained, the _Ichthyosaurus communis_
seems only to be second to the _Ichthyosaurus platyodon_. In the museum
of the Earl of Enniskillen, there is a fossil skull of the
_Ichthyosaurus communis_ which measures, in length, two feet nine
inches, indicating an animal of at least twenty feet in length.
Plesiosaurus.
The discovery of this genus forms one of the most important additions
that geology has made to comparative anatomy. Baron Cuvier deemed “its
structure to have been the most singular, and its characters the most
monstrous, that had been yet discovered amid the ruins of a former
world.” To the head of a lizard it united the teeth of a crocodile, a
neck of enormous length, resembling the body of a serpent, a trunk and
tail having the proportions of an ordinary quadruped, the ribs of a
chameleon, and the paddles of a whale. “Such,” writes Dr. Buckland, “are
the strange combinations of form and structure in the Plesiosaurus, a
genus, the remains of which, after interment for thousands of years
amidst the wreck of millions of extinct inhabitants of the ancient
earth, are at length recalled to light by the researches of the
geologist, and submitted to our examination, in nearly as perfect a
state as the bones of species that are now existing upon the earth.”
(Op. cit., vol. v. p. 203).
The first remains of this animal were discovered in the lias of Lyme
Regis, about the year 1823, and formed the subject of the paper by the
Rev. Mr. Conybeare (now Dean of Llandaff), and Mr. (now Sir Henry) De la
Beche, in which the genus was established and named Plesiosaurus (from
the Greek words, _plesios_ and _sauros_, signifying “near” or “allied
to,” and “lizard”), because the authors saw that it was more nearly
allied to the lizard than was the Ichthyosaurus from the same formation.
The entire and undisturbed skeletons of several individuals, of
different species, have since been discovered, fully confirming the
sagacious restorations by the original discoverers of the
_Plesiosaurus_. Of these species three have been selected as the
subjects of Mr. Waterhouse Hawkins’s reconstructions and representations
of the living form of the strange reptiles.
No. 15.—Plesiosaurus macrocephalus.
The first of these has been called, from the relatively larger size of
the head, the _Plesiosaurus macrocephalus_ (No. 15), (Gr. _macros_,
long, _cephale_, head). The entire length of the animal, as indicated by
the largest remains, and as given in the restoration, is eighteen feet,
the length of the head being two feet, that of the neck six feet; the
greatest girth of the body yields seven feet.
[Illustration: No. 15. Plesiosaurus macrocephalus.]
Although Baron Cuvier and Dr. Buckland both rightly allude to the
resemblance of the fins or paddles of the Plesiosaur to those of the
whale, yet this most remarkable difference must be borne in mind, that,
whereas the whale tribe have never more than one pair of fins, the
Plesiosaurs have always two pairs, answering to the fore and hind limbs
of land quadrupeds; and the fore-pair of fins, corresponding to those in
the whale, differed by being more firmly articulated, through the medium
of collar-bones (clavicles), and of two other very broad and strong
bones (called coracoids), to the trunk (thorax), whereby they were the
better enabled to move the animal upon dry land.
Remains of the _Plesiosaurus macrocephalus_ have been discovered in the
lias of Lyme Regis, in Dorsetshire, and of Weston, in Somersetshire.
No. 16.—Plesiosaurus dolichodeirus.
Further to the left, on the shore of the Secondary Island, is a
restoration of the _Plesiosaurus dolichodeirus_, or Long-necked
Plesiosaurus (No. 16). The head in this remarkable species is smaller,
and the neck proportionally longer than in the _Plesiosaurus
macrocephalus_. The remains of the Long-necked Plesiosaur have been
found chiefly at Lyme Regis, in Dorsetshire. The well known specimen of
an almost entire skeleton, formerly in the possession of His Grace the
Duke of Buckingham, is now in the British Museum.
No. 17.—Plesiosaurus Hawkinsii.
The most perfect skeletons of the Plesiosaurus are those that have been
wrought out of the lias at Street, near Glastonbury, by Mr. Thomas
Hawkins, F.G.S., and which have been purchased by the trustees of the
British Museum. A restoration is given by Mr. Waterhouse Hawkins, at No.
17, of a species with characters somewhat intermediate between the
Large-headed and Long-necked Plesiosaurs, and which has been called,
after its discoverer, _Plesiosaurus Hawkinsii_.
The Plesiosaurs breathed air like the existing crocodiles and the whale
tribe, and appear to have lived in shallow seas and estuaries. That the
Long-necked Sea-lizard was aquatic is evident from the form of its
paddles; and that it was marine is almost equally so, from the remains
with which its fossils are universally associated; that it may have
occasionally visited the shore, the resemblance of its extremities to
those of a turtle leads us to conjecture; its motion, however, must have
been very awkward on land; its long neck must have impeded its progress
through the water, presenting a striking contrast to the organisation
which so admirably adapted the Ichthyosaurus to cut its swift course
through the waves. “May it not, therefore, be concluded that it swam
upon, or near the surface,” asks its accomplished discoverer, “arching
back its long neck like a swan, and occasionally darting it down at the
fish that happened to float within its reach? It may perhaps have lurked
in shoal-water along the coast, concealed among the sea-weed, and,
raising its nostrils to a level with the surface from a considerable
depth, may have found a secure retreat from the assaults of dangerous
enemies; while the length and flexibility of its neck may have
compensated for the want of strength in its jaws, and its incapacity for
swift motion through the water, by the suddenness and agility of the
attack which enabled it to make on every animal fitted for its prey
which came within its reach.”[5]
For the Secondary Island three species of the Plesiosaurus have been
restored, the _Plesiosaurus macrocephalus_, the _Plesiosaurus
dolichodeirus_ (Gr. _dolichos_, long, _deire_, neck), and the
_Plesiosaurus Hawkinsii_. The name “long-necked” was given to the second
of these species before it was known that many other species with long
and slender necks had existed in the seas of the same ancient period:
the third species is named after Mr. Thomas Hawkins, F.G.S., the
gentleman by whose patience, zeal, and skill, the British Museum has
been enriched with so many entire skeletons of these most extraordinary
extinct sea-lizards.
The remains of all these species occur in the lias at Lyme Regis, and at
Street, near Glastonbury; but the _Plesiosaurus Hawkinsii_ is the most
abundant in the latter locality.
[Illustration: {uncaptioned}]
NEW RED SANDSTONE.
“Trias” is an arbitrary term applied in geology to the upper division of
a vast series of red loams, shales, and sandstones, interposed between
the lias and the coal, in the midland and western counties of England.
This series is collectively called the “New Red Sandstone formation,” to
distinguish it from the “Old Red Sandstone formation,” of similar or
identical mineral character, which lies immediately beneath the coal.
The animals which have been restored and placed on the lowest formation
of the Secondary Island, are peculiar to the “triassic,” or upper
division of the “New Red Sandstone” series, which division consists, in
England, of saliferous (salt-including) shales and sandstones, from 1000
to 1500 feet thick in Lancashire and Cheshire, answering to the
formation called “Keuper-sandstone” by the German geologists; and of
sandstone and quartzose conglomerate of 600 feet in thickness, answering
to the German “Bunter-sandstone.”
The largest and most characteristic animals of the trias are reptiles of
the order
Batrachia.
The name of this order is from the Greek word _batrachos_, signifying a
frog: and the order is represented in the present animal-population of
England by a few diminutive species of frogs, toads, and newts, or
water-salamanders. But, at the period of the deposition of the new red
sandstone, in the present counties of Warwick and Cheshire, the shores
of the ancient sea, which were then formed by that sandy deposit, were
trodden by reptiles, having the essential bony characters of the
Batrachia, but combining these with other bony characters of crocodiles
and lizards; and exhibiting both under a bulk which is made manifest by
the restoration of the largest known species, (No. 16), occupying the
extreme promontory of the Island, illustrative of the lowest and oldest
deposits of the secondary series of rocks. The species in question is
called the—
No. 18.—Labyrinthodon Salamandroides.
or the Salamander-like Labyrinthodon; the latter term being from the
Greek, signifying the peculiar structure of the teeth, which differ from
all other reptiles in the huge Batrachia in question, by reason of the
complex labyrinthic interblending of the different substances composing
the teeth. The skull of the Labyrinthodon is attached to the neck-bones
by two joints or condyles, and the teeth are situated both on the proper
jaw-bones, and on the bone of the roof of the mouth called “vomer:” both
these characters are only found at the present day in the frogs and
salamanders. The hind-foot of the Labyrinthodon was also, as in the toad
and frog, much larger than the fore-foot; and the innermost digit in
both was short and turned in, like a thumb.
[Illustration: No. 18. Labyrinthodon Salamandroides.]
Consecutive impressions of the prints of these feet have been traced for
many steps in succession (as is accurately represented in the new red
sandstone part of the Secondary Island) in quarries of that formation in
Warwickshire, Cheshire, and also in Lancashire, more especially at a
quarry of a whitish quartzose sandstone at Storton Hill, a few miles
from Liverpool. The foot-marks are partly concave and partly in relief;
the former are seen upon the upper surface of the sandstone slabs, but
those in relief are only upon the lower surfaces, being, in fact,
natural casts, formed on the subjacent foot-prints as in moulds. The
impressions of the hind-foot are generally eight inches in length and
five inches in width: near each large footstep, and at a regular
distance—about an inch and a half—before it, a smaller print of the
fore-foot, four inches long and three inches wide, occurs. The footsteps
follow each other in pairs, each pair in the same line, at intervals of
about fourteen inches from pair to pair. The large as well as the small
steps show the thumb-like toe alternately on the right and left side,
each step making a print of five toes.
Foot-prints of corresponding form but of smaller size have been
discovered in the quarry at Storton Hill, imprinted on five thin beds of
clay, lying one upon another in the same quarry, and separated by beds
of sandstone. From the lower surface of the sandstone layers, the solid
casts of each impression project in high relief, and afford models of
the feet, toes, and claws of the animals which trod on the clay.
Similar foot-prints were first observed in Saxony, at the village of
Hessberg, near Hillburghausen, in several quarries of a gray quartzose
sandstone, alternating with beds of red sandstone, and of the same
geological age as the sandstones of England that had been trodden by the
same strange animal. The German geologist, who first described them,
proposed the name of _Cheirotherium_ (Gr. _cheir_, the hand, _therion_,
beast), for the great unknown animal that had left the foot-prints, in
consequence of the resemblance, both of the fore and hind feet, to the
impression of a human hand, and Dr. Kaup conjectured that the animal
might be a large species of the opossum-kind. The discovery, however, of
fossil skulls, jaws, teeth, and a few other bones in the sandstones
exhibiting the footprints in question, has rendered it more probable
that both the footprints and the fossils are evidences of the same kind
of huge extinct Batrachian reptiles.
An entire skull of the largest species discovered in the new red
sandstones of Wurtemberg; a lower jaw of the same species found in the
same formation in Warwickshire; some vertebræ, and a few fragments of
bones of the limbs, have served, with the indications of size and shape
of the trunk of the animal yielded by the series of consecutive
foot-prints, as the basis of the restoration of the _Labyrinthodon
salamandroides_, in the Secondary Island. It is to be understood,
however, that, with the exception of the head, the form of the animal is
necessarily more or less conjectural.
Nos. 19 & 20.—Labyrinthodon pachygnathus.
This name, signifying the Thick-jawed Labyrinthodon, was given by its
discoverer to a species of these singular Batrachia, found in the new
red sandstone of Warwickshire, and which bears to the largest species
the proportion exhibited by the head and fore-part of the body, as
emerging from the water, for which parts alone the fossils hitherto
discovered justify the restoration.[6]
[Illustration: Nos. 19 & 20. Section of Tooth of Labyrinthodon.
_a_ Pulp-cavity: _b b_ inflected folds of ossified capsule of
tooth.]
Nos. 21 & 22.—Dicynodon.
In 1844 Mr. Andrew G. Bain, who had been employed in the construction of
military roads in the colony of the Cape of Good Hope, discovered, in
the tract of country extending northwards from the county of Albany,
about 450 miles east of Cape Town, several nodules or lumps of a kind of
sandstone, which, when broken, displayed, in most instances, evidences
of fossil bones, and usually of a skull with two large projecting teeth.
Accordingly, these evidences of ancient animal life in South Africa were
first notified to English geologists by Mr. Bain under the name of
“Bidentals;” and the specimens transmitted by him were submitted at his
request to Professor Owen for examination. The results of the
comparisons thereupon instituted went to show that there had formerly
existed in South Africa, and from geological evidence, probably, in a
great salt-water lake or inland sea, since converted into dry land, a
race of reptilian animals presenting in the construction of their skull
characters of the crocodile, the tortoise, and the lizard, coupled with
the presence of a pair of huge sharp-pointed tusks, growing downwards,
one from each side of the upper jaw, like the tusks of the mammalian
morse or walrus. No other kind of teeth were developed in these singular
animals: the lower jaw was armed, as in the tortoise, by a trenchant
sheath of horn. Some bones of the back, or vertebræ, by the hollowness
of the co-adapted articular surfaces, indicate these reptiles to have
been good swimmers, and probably to have habitually existed in water;
but the construction of the bony passages of the nostrils proves that
they must have come to the surface to breathe air.
Some extinct plants allied to the Lepidodendron, with other fossils,
render it probable that the sandstones containing the Dicynodont
reptiles were of the same geological age as those that have revealed the
remains of the Labyrinthodonts in Europe.
The generic name Dicynodon is from the Greek words signifying “two tusks
or canine teeth.” Three species of this genus have been demonstrated
from the fossils transmitted by Mr. Bain.
The _Dicynodon lacerticeps_, or Lizard-headed Dicynodon, attained the
bulk of a walrus; the form of the head and tusks is correctly given in
the restoration (No. 21); the trunk has been added conjecturally, to
illustrate the strange combination of characters manifested in the head.
A second species, with a head so formed as to have given the animal
somewhat of the physiognomy of an owl, has been partially restored at
No. 22.
[Illustration: No. 8. Dinornis.]
FOOTNOTES
[1]Lyell, “Manual of Elementary Geology.”
[2]“The first specimens of the teeth were found by Mrs. Mantell in the
coarse conglomerate of the Forest, in the spring of 1822.”—Mantell,
“Geology of the South-East of England,” 8vo, 1833, p. 268.
[3]“Report of British Fossil Reptiles,” 1841, p. 110.
[4]Op. cit., p. 174.
[5]“Transactions of the Geological Society,” Second Series, vi. 503.
1841.
[6]Conybeare, Geol. Trans., i. 388.
BRADBURY AND EVANS, PRINTERS, WHITEFRIARS.
Transcriber’s Notes
—Silently corrected a few typos.
—Retained publication information from the printed edition: this eBook
is public-domain in the country of publication.
—In the text versions only, text in italics is delimited by
_underscores_.
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