Ichthyosaurus

“ The presence of the undigested remains of vertebræ and other bones of animals of its own species in the coprolites of the Ichthyosaurus proves, as we have already had occasion to remark, that this great Saurian must have been a most voracious monster, since it habitually devoured not only fish, but individuals of its own race—the smaller becoming the prey of the larger. The structure of the jaw of the Ichthyosaurus leads us to believe that the animal swallowed its prey without dividing it. ”

“ The range of the genus Ichthyosaurus seems to have begun with the Muschelkalk, and to have extended through the whole of the oolitic period into the cretaceous formation. The most recent stratum in which any remains of this genus have yet been found is the chalk marl at Dover, where they have been discovered by Mr. Mantell: I have found them in the gault, near Benson, Oxon. ↑ Pl. 7, is a large and nearly perfect specimen of the Ichthyosaurus Platyodon, from the lias at Lyme Regis, being one of the splendid series of Saurians, Purchased in 1834 of Mr. Hawkins by the British Museum. ”

“ It was named Ichthyosaurus (Gr. fish-lizard) by C. König in 1818 in allusion to its outward form, and is best known by nearly complete skeletons from the Lias of England and Germany. The large head is produced into a slender, pointed snout; and the jaws are provided with a row of conical teeth nearly uniform in size and deeply implanted in a continuous groove. The eye is enormous, and is surrounded by a ring of overlapping “sclerotic plates,” which would serve to protect the eye-ball during diving. ”

“ Some of the larger specimens of Ichthyosaurus which have been discovered in the Lias indicate an animal of from 20 to nearly 40 feet in length; and many species are known to have existed, whilst fragmentary remains of their skeletons are very abundant in some localities. We may therefore safely conclude that these colossal Reptiles were amongst the most formidable of the many tyrants of the Jurassic seas. ”

“ The distribution of Ichthyosaurs in time and space is wide. The earliest are found in the Middle Trias; in the Lias they are very common, fairly frequent in the Oolites, dying out with the Cretaceous epoch. They have left no descendants, being far too specialised, and their origin is quite unknown. Mixosaurus, the oldest genus, occurred in Europe, and has also been found in the Triassic strata of Spitsbergen. Ichthyosaurus, the chief genus, is known from the Liassic, Oolite, and Cretaceous strata of Europe, a famous place being Lyme Regis ”

“ The most extraordinary feature of the head, is the enormous magnitude of the eye, very much exceeding that of any living animal. [18] The expansion of the jaws must have been prodigious; their length in the larger species, (Ichthyosaurus Platyodon,) sometimes exceeding six feet; the voracity of the animal was doubtless in proportion to its powers of destruction. The neck was short, as in fishes.
Teeth.
The teeth of the Ichthyosaurus (Pl. II, B, C,) are conical, and much like those of the Crocodiles, but considerably more numerous, amounting in some cases to a hundred and eighty ”

“ 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. ”

“ The fossil which I venture to refer to the genus Ichthyosaurus is the symphysial part of a long slender mandible. The front end is wanting; and the rami have also been broken off just behind the symphysis. In its present mutilated state it measures 9 in. long, 1⋅2 transversely in front, and 2⋅1 at the posterior limit of the symphysis. Its outer surface is transversely gently convex, smooth, and finely wrinkled longitudinally. ”

“ Reptiles of the Lias.—It is not, however, the fossil fish which form the most striking feature in the organic remains of the Lias; but the reptiles, which are extraordinary for their number, size, and structure. Among the most singular of these are several species of Ichthyosaurus and Plesiosaurus. The genus Ichthyosaurus, or fish-lizard, is not confined to this formation, but has been found in strata as high as the chalk-marl and gault of England, and as low as the muschelkalk of Germany, a formation which immediately succeeds the lias in the descending order. ”

“ The ichthyosaurus was certainly a most unpleasant creature to meet alone in a narrow strait on a dark night; but if it comes to actual measurement, the very biggest ichthyosaurian skeleton ever unearthed does not exceed twenty-five feet from snout to tail. Now, this is an extremely decent size for a reptile, as reptiles go; for the crocodile and alligator, the two biggest existing lizards, seldom attain an extreme length of sixteen feet. ”

“ These diagrams of the plesiosaurus, the ichthyosaurus, the pterodactyle, give you a notion of some of these extinct reptiles. And here is a cast of the pterodactyle and bones of the ichthyosaurus and the plesiosaurus, just as fresh as if it had been recently dug up in a churchyard. Thus, in the reptile class, there are no less than half of the orders which are absolutely extinct. If we turn to the 'Amphibia', there was one extinct order, the Labyrinthodonts, typified by the large salamander-like beast shown in this diagram.
No order of fishes is known to be extinct. ”

“ 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. ”

“ Lazily basking in the sun, when it condescends to shine, and resting his clumsy carcase on the ground that forms the shore near the said geological island at Sydenham, may be seen the old fish-lizard, or Ichthyosaurus, that forms the subject of the present chapter. He looks awkward on land, as if longing to get into his native element once more, and cleave its waters with his powerful tail-fin. His “flippers” seem too weak to enable him to crawl on land. ”

“ In comparing the two, it may be said, that, as a whole, the Ichthyosaurus, though belonging by its structure to the class of Reptiles, has a closer external resemblance to the Fishes, while the Plesiosaurus is more decidedly reptilian in character. If there exists any animal in our waters, not yet known to naturalists, answering to the descriptions of the "Sea-Serpent," it must be closely allied to the Plesiosaurus. ”

“ Whether or not the name Proteosaurus, first given to any member of this order, should take precedence over the later Ichthyosaurus is still in doubt, since Home gave no specific name to his species, and the very particular purists of modern times have decided that a genus is not named unless the species is also! We moderns sometimes are inclined to impose very stringent conditions upon the older naturalists; let us hope that we shall be treated more leniently by the future naturalists! ”

“ 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. ”

“ Even our own bodies, and some of their most important organs are brought into close and direct comparison with those of reptiles, which, at first sight, appear the most monstrous productions of creation; and in the very hand and fingers with which we write their history, we recognise the type of the paddles of the Ichthyosaurus and Plesiosaurus. ”

“ 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. ”

“ Let us consider for a little some of the more conspicuous forms, referring to our illustration for their [213] portraits. Every text-book figures the well-known types of the genera Ichthyosaurus and Plesiosaurus; we need scarcely, therefore, dwell on them, except to state that the catalogues of British fossils include eleven species of the former genus and eighteen of the latter, We may, however, notice some of the less familiar points of comparison of the two genera. Both were aquatic, and probably marine. Both swam by means of paddles ”

“ HERE were in the sea in very ancient times—long before the flood—two very large and wonderful reptiles. Of them we present striking illustrations. One of them has been named the Ichthyosaurus, which means Fish Reptile. Its head somewhat resembled that of the crocodile, except that the orbit was much larger, and had the nostril placed close to it, as in the whale, and not near the end of the snout. It had four paddles and a powerful tail, and was very active in its movements and a rapid swimmer.
The other huge reptile was the Plesiosaurus, the meaning of which is “Near to a Reptile.” ”

“ The reptiles are so rare as embryos and withal so ancient a group that their ontogeny throws but little light upon paleontology. Among the fossil forms a number of specimens of Ichthyosaurus have been found with young contained within the body of the adult. Many of these are in the normal position for fœti-in-utero; others are displaced, with the head directed forward. These latter Branca thinks may be young that have been eaten. There is also, at times, a very great difference in the size of the contained young. ”

“ It is probable that every species of Ichthyosaurus had peculiar variations in the details of the cervical vertebra?, and sub vertebral wedges, and that in each species these variations were modified by age. ”

“ The vertebræ, or bony segments of the backbone, generally have their centra hollow on both sides, as in the Ichthyosaurus; but in the neck and tail they are not unfrequently hollow on one side and convex on the other. In some of the largest forms the vertebræ are excavated into hollow chambers. This is apparently for the sake of lightness; for a very large animal with heavy solid bones would find it difficult to move freely. In this way strength was combined with lightness.
All the Dinosaurs had four limbs, and in many cases the hind pair were very large compared to the fore limbs. ”

“ The bones of a fore-paddle of an Ichthyosaurus are represented (Lign. 214, fig. 1) . In some species each paddle consists of nearly one hundred bones. These locomotive extremities are very analogous in their osteological construction to those of the Cetaceans, but they are connected with the trunk by means of the glenoid socket formed by the scapula and coracoid, which are firmly united to the sternum; whereas in the Cetaceans the pectoral fin is only attached to a simple scapula, which is merely suspended in the muscles. ”

“ The Actinopharis, (Actinopharis Elhornii,) on the right points to the Rhizopods, and the Ferns and Fungi beneath are representatives of Cryptogamic Botany. The Apteryx, (Apteryx Australis,) and Octopus, (Octopus vulgaris,) represent rare and curious animals, and at the same time point to Ornithology and the Mollusca. The Ichthyosaurus at the base is a representative of animals long extinct, and now found in a fossil condition only. ”

“ On the other hand, I think it must be admitted that a belief in the continuity of the modern with the ancient chalk has nothing to do with the proposition that we can, in any sense whatever, be said to be still living in the Cretaceous epoch. When the Challenger's trawl brings up an Ichthyosaurus, along with a few living specimens of Belemnites and Turrilites, it may be admitted that she has come upon a cretaceous "outlier." A geological period is characterized not only by the presence of those creatures which lived in it, but by the absence of those which have only come into existence later ”

“ This enormous creature was, of course, like Diplodocus, aquatic. Its bulk was much less than that of a big whale, but extinct aquatic reptiles may yet be found of greater size. Ichthyosaurus, the extinct whale-like reptile, does not exceed 30 ft. in length. Our engraving (Fig. 32) shows the relative size of the humerus of man, the elephant, [4] and the Gigantosaurus. How puny is that human arm-bone! And yet...!
When stretched on the shore, resting on the belly, the body of the great lizard of Tendagoroo bulked like a breakwater 12 ft. high, and his tail like a huge serpent extended 80 ft. ”

“ Nor do the Eocene mammals fall short of the marvellous, for in Dinoceras we find a beast with six horns, and sword-bayonet tusks, joined to a skeleton like an elephant.
Latest amongst the marvels in modern palæontological discovery has been that made by Professor Fraas of the outline of the skin and fins in Ichthyosaurus tenuirostris, which shows it to have been a veritable shark-like reptile, with a high dorsal fin and broad fish-tail, so that “fish-lizard” is more than ever an appropriate term for these old Liassic marine reptiles. ”

“ It has already been shown how the great saurians Ichthyosaurus and Plesiosaurus presumed to put on some of the characters of whales, and to play their rôle in nature, though they were only reptiles; how the carnivorous Dinosaurs acquired teeth like those now possessed by lions and tigers, which also are mammals; and now we find herbivorous Dinosaurs imitating the Glyptodon, an armadillo that lived in South America almost down to the human period. We shall not lose sight of this very interesting and curious discovery, for other cases will present themselves to our view in future chapters. ”