The World Before the Deluge

Shells are the only traces which remain of the Ammonites. We have no exact knowledge of the animal which occupied and built them. The attempt at restoration, as exhibited in Fig. 91, will probably convey a fair idea of the Ammonite when living. We assume that it resembled the Nautilus of modern times. What a curious aspect these early seas must have presented, covered by myriads of these Molluscs of all sizes, swimming about in eager pursuit of their prey!

The Ammonites of the Jurassic age present themselves in a great variety of forms and sizes; some of them of great beauty. Atntnon-ites bifrons, A. Noditiaims, A. bisulcatits, A. Tinmeri (Fig. 90), and A. margaritaius^ are forms characteristic of the Lias.

The Bekmnitcs^ molluscous Cephalopods of a ver}' curious organisation, appeared in great numbers, and for the first time, in the Jurassic seas. Of this Mollusc we only possess the fossilised internal " bone," analogous to that of the modern cuttle-fish and thecalamary of the present seas. This simple relic is very far from giving us an exact idea of what the animal was to which the name of Belemnite has been given (from BeAe^i'oj/, a dart) from their supposed resemblance to the head of a javelin. The slender cylindrical bone, the only vestige remaining to us, was merely the internal skeleton of the

2l6 THE WORLD BEFORE THE DELUGE.

animal. When first discovered they were called, by the vulgar, "Thunder-stones'' and "Ladies' fingers." They were, at last,

Fig. 91. — Ammonite restored.

Fig. 92.— Belemnite restored.

inferred to be the shelly processes of some sort of ancient cuttlefish. Unlike the Ammonite, which floated on the surface and sunk to the bottom at pleasure, the Belemnite, it has been thought, swam nearer the bottom of the sea, and seized its ^^rey from below.

THE LIAS,

In Fig. 92 is given a restoration of the living Belemnite, by Dr. Buckland and Professor Owen, in which the terminal part of the animal is marked in a slightly darker tint, to indicate the place of the bone which alone represents in our days this fossilised being. A sufficiently exact idea of this Mollusc may be arrived at from the existing cuttle-fish. Like the cuttle-fish, the Belemnite secreted a black liquid, a sort of ink or sepia; and the bag containing the ink has frequently been found in a fossilised state, with the ink dried up, and elaborate drawings have been made with this fossil pigment. The beaks, or homy mandibles of the mouth, which the Belemnite possessed in common with the other naked Cephalopoda, are rejoresented in Fig. 78, p. 181.

As Sir H. De la Beche has pointed out, the destruction of the animals whose remains are known to us by the name of Belemnites was exceedingly great when the upper part of the Lias of Lyme Regis was deposited. Multitudes seem to have perished almost simultaneously, and millions are entombed in a bed beneath Golden Cap, a lofty cliff between Lyme Regis and Bridport Harbour, as well as in the upper Lias generally.'^

Among the Belemnites characteristic of the Liassic period may be cited B. acutiis {Yig. 93), B. pisiilifonnis, and B. sulcaius. The seas of the period contained a great number of the fishes called Ganoids; which are so called from the splendour of the hard and enamelled scales, which formed a sort of defensive armour to protect their bodies. Lepidotics gigas was a fish of great size belonging to this age. A smaller fish was the Tetragonoiepis, or y^chmodus Buchii. The Acrodus nobilis^ of which the teeth are still preserved, and popularly known by the name of Fig. 93. fossil leeches^ was a fish of which an entire skeleton has acutus.*^ never been met with. Neither are we better informed as to the Hybodus retiadatus. The bony spines, which form the anterior part of the dorsal fin of this fish, had long been an object of curiosity to geologists, under the general name of Ichthyodorulites^ before they were known to be fragments of the fin of the Hybodus, The Ichthyodorulites were supposed by some naturalists to be the jaw of some animal — by others, weapons like those of the living

De la Beche's " Geological Manual," 3rd ed., p. 447.

Balistes or Silurus; _ 3 but Agassiz has shown them to be neither the one nor the other, but ‘bony spines on the fin, like those of the living genera of Cestracions and Chimeras, in both of which the concave face is armed with small spines like those of the Hybodus. The spines were simply imbedded in the flesh, and attached to it by strong muscles. “ They served,” says Dr. Buckland, “as in the Chimera, to raise and depress the fin; their action resembling that of a moy-able mast lowering backward.” “Let us hasten to say, however, that these are not the beings that characterised the age, and were the salient features of the generation of animals which existed during the Jurassic period. These distinguishing features are found in the enormous reptiles with lizard’s head, crocodile’s conical teeth, the trunk and tail of a quadruped, whale-like paddles, and the double-concave vertebre of fishes; and this strange form, on such a gigantic scale that even their inanimate remains are examined with a curiosity not unmixed with awe. The’ country round Lyme Regis, in Dorsetshire, has long been celebrated for the curious fossils discovered in its quarries, and preserved in the muddy accumulations of the sea of the Liassic period. The country is hilly—“up one hill and down another,” is a pretty correct provincial description of the walk from Bridport to Lyme Regis—

Fig. 94. -Ichthyosaurus communis. Where some of the most frightful creatures the living world has probably ever

GOBBI RBI

G ZS Blar 777? Ae nes Vee iM cy

THE LIAS.

beheld, sleep the sleep of stones. The quarries of Lyme Regis form the cemetery of the Ichthyosauri; the sepulchre where lie interred these dragons of the ancient seas.

In 181 1 a country girl, who made her precarious living by picking up fossils for which the neighbourhood was famous, was pursuing her avocation, hammer in hand, when she perceived some bones projecting alittle out of the cliff. Finding, on examination, that it was part of a large skeleton, she cleared away the rubbish, and laid bare the whole creature imbedded in the block of stone. She hired workmen to dig out the block of Lias in which it was buried. In this manner was the first of these monsters brought to light: " a monster some thirty feet long, with jaws nearly a fathom in length, and huge

Fig. g5.— Head of Ichthyosaurus platydon.

saucer-eyes; v ' ''^h have since been found so perfect, that the petrified lenses have been split off and used as magnifiers," as a writer in All the Year Roimd assures us.

In Fig. 95 the head of /. platydon is represented. As in the Saurians, the openings of the nostrils are situated near the anterior angle of the orbits of the eyes, while those of the Crocodile are near the snout; but, on the other hand, in its osteology and its mode of dentition it nearly resembles the Crocodile; the teeth are pointed and conical — not, however, set in deep or separate sockets, but only implanted in a long and deep continuous groove hollowed in the bones of the jaw. These strong jaws have an enonnous opening; for, in some instances, they have been found eight feet in length and armed with 160 teeth. Let us add that teeth lost through the voracity of the animal, or in contests with other animals, could be renewed

many times; for, at the inner side of the base of every old tooth, there is ahvays the bony germ of a new one.

The eyes of this marine monster were much larger than those of any animal now living; in volume they frequently exceed the human head, and their structure was one of their most remarkable peculiarities. In front of the sclerotic coat or capsule of the eye there is an annular series of thin bony plates, surrounding the pupil. This structure, which is now only met with in the eyes of certain turtles, tortoises, and lizards, and in those of many birds, could be used so as to increase or diminish the curvature of the transparent cornea, and thus increase or diminish the magnifying power, according to the requirements of the animal — performing the office, in short, of a telescope or microscope at pleasure. The eyes of the Ichthyosaurus were, then, an optical apparatus of wonderful power and of singular perfection, enabling the animal, by their power of adaptation and intensity of vision, to see its prey far and near, and to pursue it in the darkness and in the depths of the sea. The curious arrangement of bony plates we have described furnished, besides, to its globular eye, the power necessary to bear the pressure of a considerable weight of water, as well as the violence of the waves, when the animal came to the surface to breathe, and raised its head above the waves. This magnificent specimen of the fish-lizard, or Ichthyosaurus, as it was named by Dr. Ure, now forms part of the treasures of the British Museum.

At no period in the earth's history have Reptiles occupied so important a place as they did in the Jurassic period. Nature seems to have wished to bring this class of animals to the highest state of development. The great Reptiles of the Lias are as complicated in their structure as the Mammals which appeared' at a later period. They probably lived, for the most part, by fishing in shallow creeks and bays defended from heavy breakers, or in the open sea; but they seem to have sought the shore from time to time; they crawled along the beach, covered with a soft skin, perhaps not unlike some of our Cetace^e. The Ichthyosaurus, from its form and strength, may have braved the waves of the sea as the porpoise does now. Its destructiveness and voracity must have been prodigious, for Dr. Buckland describes a specimen which had between its ribs, in the place where the stomach might be supposed to have been placed, the skeleton of a smaller one — a proof that this monster, not content with preying on its weaker neighbours, was in the habit of devouring its own kind. In the same waters lived the Plesiosaunis, with long neck and form more strange than that of the Ichthyosaurus; and these potentates of

the seas were warmed by the same sun and tenanted the same banks, in the midst of a vegetation not unUke that which the climate of Africa now produces. The great Saurians in the Lias of Lyme Regis seem to have suffered a somewhat sudden death, partly in consequence of a series of small catastrophes suddenly destroying the animals then existing in particular spots. " In general the bones are not scattered about, and in a detached state, as would happen if the dead animal had descended to the bottom of the sea, to be decomposed, or devoured piecemeal, as, indeed, might also happen if the creature floated for a time on the surface, one animal devouring one part, and another carrying off a different portion; on the contrary, the bones of the skeleton, though frequently compressed, as must arise from the enormous pressure to which they have so long been subjected, are tolerably connected, frequently in perfect, or nearly perfect, order, as if prepared by the anatomist. The skin, moreover, may sometimes be traced, and the compressed contents of the intestines may at times be also observed — all tending to show that the animals were suddenly destroyed, and as suddenly preserved."'''"