still more monstrous than the ichthyosaurus. It had the same limbs,
but somewhat more elongated and more flexible; its shoulder and
pelvis were more robust; its vertebræ had more of the forms and
articulations of the lizards; but what distinguished it from all
oviparous and viviparous quadrupeds, was a slender neck as long as
its body, composed of thirty and odd vertebræ, a number greater than
that of the neck of any other animal, rising from the trunk like the
body of a serpent, and terminating in a very small head, in which all
the essential characters of that of the lizard family are observed.
If any thing could justify those hydras and other monsters, the
figures of which are so often presented in the monuments of the
middle ages, it would incontestibly be this plesiosaurus.[250]
Five species are already known, of which the most generally
distributed (_P. dolichodeirus_) attains a length of more than twenty
feet.
A second species (_P. recentior_), found in more modern strata, has
the vertebræ flatter.
A third (_P. carinatus_) shews a ridge on the under surface of its
vertebræ.
A fourth, and lastly a fifth (_P. pentagonus_ and _P. trigonus_),
have the ribs marked with five and three ridges.[251]
These two genera are found everywhere in the lias: they were
discovered in England, where this rock is exposed in cliffs of great
extent; but they have also been found since in France and Germany.
Along with these had lived two species of Crocodiles, the bones
of which are also found deposited in the lias, among ammonites,
terebratulæ, and other shells of that ancient sea. We have skeletons
of them in our cliffs at Honfleur, where the remains are found, from
which I have drawn up their characters.[252]
One of these species, the _Long-beaked Gavial_, has the muzzle
longer, and the head more narrow, than the gavial or long-beaked
crocodile of the Ganges; the bodies of its vertebræ are convex
before, while in our crocodiles of the present day they are so
behind. It has been found in the lias deposits of Franconia, as well
as in those of France.
A second species, the _Short-beaked Gavial_, has the muzzle of
ordinary length, less attenuated than the gavial of the Ganges, but
more so than our crocodiles of St Domingo. Its vertebræ are slightly
concave at each of their extremities.
But these crocodiles are not the only ones which have been deposited
in the strata of these secondary limestones.
The beautiful oolite quarries of Caen have presented a very
remarkable one, the muzzle of which is as long and more pointed than
that of the long-beaked gavial, and its head more dilated behind,
with wider temporal fossæ. Its stony scales, marked with small
round cavities, must have rendered it the best defended of all the
crocodiles.[253] Its lower teeth are alternately longer and shorter.
There is still another in the oolite of England; but there have only
been found some portions of its cranium, which do not suffice to
afford a complete idea of it.[254]
Another very remarkable genus of reptiles, the remains of which,
although they are also found beyond the limits of the lias
concretion, are especially abundant in the oolite and upper sands, is
the _megalosaurus_, justly so named, for, along with the forms of the
lizards, and particularly of the monitors, of which it has also the
sharp-edged and dentated teeth, it presents so enormous a size, that
if we suppose it to have possessed the proportions of the monitors,
it must have exceeded seventy feet in length. It was, in fact, a
lizard of the size of a whale.[255] It was discovered by Mr Buckland
in England; but we have it also in France; and in Germany there are
found bones, if not of the same species, at least of a species which
can be referred to no other genus. It is to M. Sœmmering that we owe
the first description of this last. He discovered the bones in strata
lying above the oolite, in those limestone-schists of Franconia, long
celebrated for the numerous fossil remains which they furnished to
the cabinets of the curious, and which will be still more celebrated
for the services which their employment in lithography render to the
arts and sciences.
The crocodiles continue to make their appearance in these schists,
and always of the long-muzzled or rostrated kind. M. de Sœmmering
has described one (the _Crocodilus priscus_), the entire skeleton of
a small individual of which was found nearly in as good a state of
preservation, as it could have been in our cabinets.[256] It is one
of those which most resemble the present gavial of the Ganges; the
anterior or united part of its lower jaw, however, is less elongated;
its lower teeth are alternately and regularly longer and shorter. It
has ten vertebræ in the tail.
But the most remarkable animals which these limestone slates contain,
are the flying lizards, which I have named _Pterodactyli_.
They are reptiles whose principal characters are, a very short tail,
a very long neck, the muzzle much elongated, and armed with sharp
teeth; the legs also long, and one of the toes of the anterior
extremity excessively elongated, having probably served for the
attachment of a membrane adapted for supporting them in the air,
accompanied with four other toes of ordinary size, terminated by
hooked claws. One of these strange animals, whose appearance would be
frightful did they occur alive at the present day, may have been of
the size of a thrush[257], the other of that of a common bat[258];
but it would appear from some fragments that larger species had
existed[259].
A little above the limestone slates is found the nearly homogeneous
limestone of the Jura ridges. It also contains bones, but always of
reptiles, crocodiles, and fresh-water tortoises, of which a vast
quantity is found in particular in the neighbourhood of Soleure.
They have been very carefully searched for by M. Hugi; and, from the
fragments which he has already collected, it is easy to recognise
a considerable number of Fresh-water Tortoises, or Emydes, which
further discoveries can alone determine, but of which several are
already distinguished by their size and peculiar forms, from all the
species hitherto known[260].
It is among these innumerable oviparous quadrupeds, of all sizes and
forms; in the midst of these crocodiles, tortoises, flying reptiles,
huge megalosauri, and monstrous plesiosauri, that some small
Mammifera are said to make their appearance for the first time; and
the assertion is so far authenticated by the occurrence of jaws, and
some other bones discovered in England, which undoubtedly belong to
this class of animals, and particularly to the family of Didelphides,
or to that of the Insectivora.
It may, however, be supposed, that the stoney matters which encrust
these bones, owe their origin to some local recomposition, posterior
to the original formation of the strata. However this may be, it is
still found for a long time that the class of Reptiles predominates.
The ferruginous sands, placed in England above the chalk, contain
abundance of crocodiles, tortoises, megalosauri, and especially a
reptile which presents a character quite peculiar, in as much as its
teeth appear worn, like those of our herbivorous mammifera.
To Mr Mantell of Lewes, in Sussex, we are indebted for the
discovery of this latter animal, as well as of other large reptiles
belonging to the sands lying beneath the chalk. He has named it
_Iguanodon_[261].
In the chalk itself there are only reptiles to be seen: there are
found in it remains of tortoises and crocodiles. The famous tufaceous
quarries of the mountain of St Peter, near Maestricht, which belong
to the chalk formation, along with very large sea tortoises, and a
multitude of marine shells and zoophytes, have afforded a genus of
lizards not less gigantic than the megalosaurus, which has become
celebrated by the researches of Camper, and the figures which Faujas
has given of its bones, in his history of that mountain.
It was upwards of five and twenty feet long; its large jaws were
armed with very strong conical teeth, a little arcuate, and marked
with a ridge, and it had also some of these teeth in the palate.
Upwards of a hundred and thirty vertebræ were counted in its spine;
they were convex before, and concave behind. Its tail was deep and
flat, and formed a large vertical oar (or organ of swimming).[262] Mr
Conybeare has recently proposed to name it _Mosasaurus_.
The clays and lignites which cover the upper part of the chalk, I
have only found to contain crocodiles[263]; and I have every reason
to think that the lignites which in Switzerland have afforded beaver
and mastodon bones, belong to a later epoch. Nor has it been at an
earlier period than that of the coarse limestone which rests upon
these clays that I have begun to find bones of mammifera; and still
do they all belong to marine mammifera, to dolphins of unknown
species, lamantins and morses.
Among the dolphins, there is one, the muzzle of which, more elongated
than that of any known species, has the lower jaw united in a
considerable part of its length, nearly as in a gavial. It was found
near Dax by the late president of Borda[264].
Another species, from the cliffs of the Department de l’Orne, has the
muzzle also long, but somewhat differently shaped[265].
The entire genus of lamantins is at the present day confined to
the seas of the torrid zone; and that of the morses, of which only
a single living species is known to exist, is limited to the frozen
ocean. Yet we find skeletons of these two genera side by side in the
coarse limestone strata of the middle of France; and this association
of species, the nearest allied to which are, at the present day,
found in opposite zones, will again make its appearance more than
once as we proceed.
Our fossil lamantins differ from those known to exist at present, in
having the head more elongated, and of a different form[266]. Their
ribs, which are easily recognised by their being of a thick and
rounded form, and of dense texture, are not of rare occurrence in our
different provinces.
With regard to the fossil morse, small fragments only have as yet
been found of it, which are insufficient for characterising the
species[267].
It is only in the strata that have succeeded the coarse limestone,
or, at most, those which may have been of contemporaneous formation
with it, but deposited in fresh-water lakes, that the class of land
mammifera begins to shew itself in any quantity.
I consider as belonging to the same period, and as having lived
together, but perhaps in different spots, the animals whose bones are
deposited in the molasse and old gravel beds of the south of France;
in the gypsums mixed with limestone, such as those of Paris and Aix;
and in the fresh-water marly deposits covered with marine beds, of
Alsace, the country of Orleans and of Berry.
This animal population possesses a very remarkable character in
the abundance and variety of certain genera of pachydermata, which
are entirely awanting among the quadrupeds of our days, and whose
characters have more or less resemblance to those of the tapirs, the
rhinoceroses, and camels.
These genera, the entire discovery of which is my own, are the
_palæotheria_, _lophiodonta_, _anaplotheria_, _anthracotheria_,
_cheropotami_, and _adapis_.
The _Palæotheria_ have resembled the tapirs in their general form,
and in that of the head, particularly in the shortness of the bones
of the nose, which announces that they have had a small proboscis
like the tapirs, and, lastly, in their having six incisors and two
canine teeth in each jaw; but they have resembled the rhinoceros in
their grinders, of which those of the upper jaw have been square,
with prominent ridges of various configuration, and those of the
lower jaw in the form of double crescents, as well as in their feet,
all of which have been divided into three toes, while in the tapirs
the fore feet have four.
It is one of the most extensively diffused genera and most numerous
in species that occur in the deposits of this period.
Our gypsum quarries in the neighbourhood of Paris are full of them.
Bones of seven distinct species are found there. The first (_P.
magnum_) is as large as a horse. The three next are of the size of a
hog, but one of them (_P. medium_) has narrow and long feet, another
(_P. crassum_) has the feet broader, and a third (_P. latum_) has
them still broader, and especially shorter. The fifth species (_P.
curtum_), which is of the size of a sheep, is much lower, and has
the feet still broader and shorter in proportion than the last. The
sixth (_P. minus_) is of the size of a small sheep, and has long and
slender feet, the lateral toes of which are shorter than the rest.
The seventh (_P. minimum_), which is not larger than a hare, has also
the feet slender[268].
Palæotheria have also been found in other districts of France: at Puy
in Valey, in strata of gypseous marl, a species (_P. velaunum_)[269],
much resembling (_P. medium_), but differing from it in the form of
its lower jaw; in the neighbourhood of Orleans, in strata of marly
rock, a species (_P. aurelianense_)[270], which is distinguished from
the others by having the re-entering angle of the crescent of its
lower grinders split into a double point, and by some differences
in the necks of the upper grinders; near Issel, in a bed of gravel
or molasse, along the declivities of the Black Mountain, a species
(_P. isselanum_)[271], which has the same characters as the Orleans
species, but is of smaller size. It is more particularly, however, in
the molasse of the Department of the Dordogne, that the palæotherium
occurs not less abundantly than in our gypsum deposits in the
neighbourhood of Paris.
The Duke Decaze has discovered in the quarries of a single field,
bones of three species which appear different from all those of our
neighbourhood[272].
The _Lophiodons_ approach still somewhat nearer to the tapirs than
the palæotheria do, inasmuch as their lower false grinders have
transverse necks like those of the tapirs.
They differ, however, from these latter, in having the fore ones more
simple, the backmost of all with three necks, and the upper ones
rhomboidal, and marked with ridges very much resembling those of the
rhinoceros.
We are still ignorant what the form of their snout, and the number
of their toes, may have been. I have discovered not less than twelve
species of this genus, all in France, deposited in marly rocks of
fresh-water formation, and filled with lymneæ and planorbes, which
are shells peculiar to pools and marshes.
The largest species is found near Orleans, in the same quarry as the
palæotheria; it approaches the rhinoceros.
There is a smaller species in the same place; a third occurs at
Montpellier; a fourth near Laon; two near Buchsweiler in Alsace;
five near Argenton in Berry; and one of the three occurs again near
Issel, where there are also two others. There is also a large one
near Gannat[273].
These species differ from each other in size, the smallest being
scarcely so large as a lamb of three months, and in various
circumstances connected with the form of their teeth, which it would
be too tedious and minute to detail here.
The _Anoplotheria_ have hitherto been discovered nowhere but in
the gypsum quarries of the neighbourhood of Paris. They have two
characters which are observed in no other animal; feet with two
toes, the metacarpal and metatarsal bones of which are separate in
their whole length, and do not unite into a single piece, as in the
ruminantia; and teeth placed in a continuous series without any
interruption. Man alone has the teeth so placed in mutual contiguity,
without any interval. Those of the anaplotheria consist of six
incisors in each jaw, a canine tooth and six grinders on each side,
both above and below; their canine teeth are short and similar to
the outer incisors. The three first grinders are compressed; the
four others are, in the upper jaw, square, with transverse ridges,
and a small cone between them; and, in the lower jaw, in the form of
a double crescent, but without neck at the base. The last has three
crescents. Their head is of an oblong form, and does not indicate
that the muzzle has terminated either in a proboscis or a snout.
This extraordinary genus, which can be compared to nothing in living
nature, is subdivided into three subgenera: the _Anaplotheria_,
properly so called, the anterior molares of which are still pretty
thick, and the posterior ones of the lower jaw have their crescents
with a simple ridge; the _Xiphodons_, of which the anterior molares
are thin and sharp on the edges, and the under posterior, have,
directly opposite the concavity of each of their crescents, a point,
which, on being worn, also assumes the form of a crescent, so that
then the crescents are double as in the ruminantia; lastly, the
_Dichobunes_, the outer crescents of which are also pointed at the
beginning, and which have thus points disposed in pairs upon their
lower posterior grinders.
The most common species in our gypsum quarries (_An. commune_), is
an animal of the height of a boar, but much more elongated, and
furnished with a very long and very thick tail, so that altogether it
has nearly the proportion of the otter, but larger. It is probable
that it was well fitted for swimming, and frequented the lakes in the
bottom of which its bones have been incrusted by the gypsum which was
deposited there. We have one a little smaller, but in other respects
pretty similar (_An. secundarium_.)
We are as yet acquainted with only one _xiphodon_, which, however,
is a very remarkable animal: it is that which I have named _An.
gracile_. It is slender, and delicately formed, like the prettiest
gazelle.
There is one _dichobune_, nearly of the size of a hare, to which
I have given the name of _An. leporinum_. Besides its subgeneric
characters, it differs from the anaplotheria and xiphodons, in having
two small and slender toes on each foot, at the sides of the two
large toes.
We do not know if these lateral toes exist in the two other
dichobunes, which are small, and scarcely exceed in size the common
Guinea pig[274].
The genus of _Anthracotheria_ is in some degree intermediate between
the palæotheria, anaplotheria, and hogs. I have named it so, because
two of its species have been found in the lignites of Cadibona, near
Savone. The first approached the rhinoceros in size; the second was
much smaller. They have also been found in Alsace, and in the Vélay.
Their grinders are similar to those of the anaplotheria; but they
have projecting canine teeth[275].
The genus _Cheropotamus_ is found in our gypsum deposits, where it
accompanies the palæotheria and anaplotheria, but where it is of
much rarer occurrence. Its posterior grinders are square above,
rectangular below, and have four large conical eminences surrounded
with smaller ones. The anterior molares are short cones, slightly
compressed, and with two roots. Its canine teeth are small. Neither
its incisors nor its feet are yet known. I possess only one species,
which is of the size of a Siam hog[276].
The genus _Adapis_ has also but one species, which is at most of the
size of a rabbit: it is also from our gypsum quarries, and must have
been nearly allied to the anaplotheria[277].
We have thus nearly forty species of pachydermata belonging to genera
now entirely extinct, and presenting forms and proportions to which
there is nothing that can be compared in the present animal kingdom,
excepting two tapirs and a daman.
This large number of pachydermata is so much the more remarkable,
that the ruminantia, which are at present so numerous in the genera
of deer and antelopes, and which attain so great a size in those of
the oxen, giraffes, and camels, scarcely make their appearance in the
deposits of which we are speaking.
I have not seen the slightest trace of them in our gypsum quarries;
and all that has come to my hands consists of some fragments of a
deer, of the size of the roe, but of a different species, collected
among the palæotheria of Orleans[278]; and of one or two other small
fragments, from Switzerland, which, however, are perhaps of doubtful
origin.
But our pachydermata have not for all this been the only inhabitants
of the countries in which they lived. In our gypsum deposits, at
least, we find along with them carnivora, glires, several sorts of
birds, crocodiles, and tortoises; and these two latter genera also
accompany them in the molasse sandstones and marly deposits of the
middle and south of France.
At the head of the carnivora, I place a Bat, very recently
discovered at Montmartre, and which belongs to the proper genus
Vespertilio[279]. The existence of this genus, at an epoch so remote,
is so much the more surprising, that, neither in this formation, nor
in those which have succeeded it, have I seen any other trace, either
of cheiroptera or of quadrumana: no bone or tooth of either monkey
or maki has ever presented itself to me, in the course of my long
researches.
Montmartre has also furnished the bones of a fox different from ours,
and which also differs from the jackals, isatises, and the various
species of foxes peculiar to America[280]; those of a carnivorous
animal allied to the raccoons and coaties, but larger than any known
species[281]; those of a particular species of civet[282]; and of
two or three other carnivora, which it has not been possible to
determine, from the want of tolerably complete portions.
What is still more remarkable, is, that there are skeletons of a
small sarigue, allied to the marmose, but different, and consequently
of an animal belonging to a genus which is at the present day
confined to the New World[283]. Skeletons of two small glires, of the
genus myoxus[284], and a skull belonging to the genus sciurus[285],
have also been collected.
Our gypsum deposits are more fertile in bones of birds than any
of the other strata either anterior or posterior to it. Entire
skeletons, and parts of at least ten species belonging to all the
orders, are found there[286].
The crocodiles of the period in question approach our common
crocodiles in the form of the head, while, in the deposits of the
Jura period, we find only species allied to the gavial.
A species has been found at Argenton, which is remarkable for its
compressed, sharp teeth, having their edges dentated like those of
certain monitors[287]. Some remains of it also occur in our gypsum
quarries[288].
The tortoises of this period are all fresh-water ones: some of
them belong to the subgenus _Emys_; and there are species, both at
Montmartre[289], and still more especially in the molasse sandstones
of the Dordogne[290], which are larger than any living species known;
the others are Trionyces or soft tortoises[291]. This genus, which
is easily distinguished by the vermiculate surface of the bones of
its shell, and which at present exists only in the rivers of warm
countries, such as the Nile, the Ganges, and the Orinoko, has
been very abundant in the places where the palæotheria lived. Vast
quantities of its remains are found at Montmartre[292], and in the
molasse sandstones of the Dordogne, and the other gravel deposits of
the south of France.
The fresh-water lakes, around which these various animals have lived,
and which had received their bones, nourished, besides the tortoises
and crocodiles, some fishes and testaceous mollusca. All that have
been collected of these two classes of animals, are as foreign to
our climate, and even as much unknown in our present waters, as the
palæotheria, and other quadrupeds which were coeval with them[293].
The fishes have even in part belonged to unknown genera.
Hence, it cannot be doubted that this race of inhabitants, which
might be termed the population of the middle age, this first great
production of mammifera, has been entirely destroyed; and, in fact,
in all places where remains of them have been discovered, there are
great deposits of marine formation above them, so that the sea has
overwhelmed the countries which these races inhabited, and has
rested upon them during a long period of time.
Have the countries inundated by it at this period been of great
extent? This is a question which the examination of those ancient
deposits formed in their lakes do not enable us to answer.