Plesiosaurus

“ Conjectural Restoration of the Skeleton of Plesiosaurus dolichodeirus. (Conybeare.)
⁠2. Skeleton of Plesiosaurus dolichodeirus, in the British Museum, from the Lias at Lyme Regis. (Scharf. Original.)
Plate 17. V. I. p. 158.
A nearly, entire and unique skeleton of Plesiosaurus dolichodeirus, 5 feet 7 inches long, from the Lias of Street, near Glastonbury. This skeleton forms part of the splendid series of fossil Saurians, purchased for the British Museum, from T. Hawkins, Esq. in 1834. See V. I. p. 162, and Note. (Hawkins.) ”

“ 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. ”

“ A plesiosaurus, or some other of the huge marine reptiles usually believed to be extinct, might certainly have produced the phenomena described, granting the possibility of one having survived to the present time. ”

“ In the same formation are found the remains of another ancient reptile, called the Plesiosaurus, that is to say, nearly allied to the Lizard. Of this extraordinary monster Cuvier observed that its structure was the most singular and anomalous that, up to his time, had been discovered 181 amid the ruins of the ancient world. It is chiefly distinguished from the Ichthyosaurus, to which it has no small affinity, by the enormous length of its neck, which, in some species, resembles the body of a serpent. Dr. Buckland tells us that in the Plesiosaurus Dolichodeirus the neck is longer than the trunk ”

“ 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. ”

“ Plesiosaurus, plē-zi-o-saw′rus, n. the type or leading genus of a family (Plesiosauridæ) of fossil sea-reptiles, which are characteristic of the Mesozoic systems. [Gr. plēsios, near, sauros, lizard.]
Plethora, pleth′o-ra, n. excessive fullness of blood: over-fullness in any way.—adjs. Plethore′tic, Plethor′ic, -al, afflicted with plethora: superabundant: turgid.—adv. ”

“ If the rock in which the skeleton of a plesiosaurus is embedded had been deposited as slowly as it is supposed to have been deposited, every trace of organization must have decomposed and disappeared long ages before the animal could have been covered up in its bed. ”

“ More than twenty species of long-necked sea-lizards are known to geologists.
Professor Owen, in his great work on British Fossil Reptiles, when describing the huge Plesiosaurus dolichodeirus from Dorset, suggests that the carcase of this monster, after it sank to the [59] bottom of the sea, was preyed upon by some carnivorous animal (perhaps sharks) . It seems, he says, as if a bite of the neck had pulled out of place the eighth to the twelfth vertebræ. Those at the base of the neck are scattered and dispersed as if through more “tugging and riving.” ”

“ Songless, silent, hushed, with never bird or insect,
Veiled with spreading fronds and screened with tall club-mosses,
Lycopodiacea,—
"When beside thee walked the solemn Plesiosaurus,
And all around thee crept the festive Ichthyosaurus,
While from time to time above thee flew and circled
Cheerful Pterodactyls;—
[Pg 47]
"Tell us of thy food,—those half-marine refections,
Crinoids on the shell, and Brachipods au naturel,—
Cuttle-fish to which the pieuvre of Victor Hugo
Seems a periwinkle.
"Speak, thou awful vestige of the Earth's creation—
Solitary fragment of remains organic! ”

“ 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. ”

“ Among those common to the English bone-bed and the Muschelkalk of Germany are Hybodus plicatilis (Fig. 386) , Saurychthys apicalis (Fig. 387) , Gyrolepis tenuistriatus (Fig. 388) , and G. Albertii. Remains of saurians, Plesiosaurus among others, have also been found in the bone-bed, and plates of an Encrinus. It may be questioned whether some of those fossils which have the most Triassic character may not have been derived from the destruction of older strata, since in bone-beds, in general, many of the organic remains are undoubtedly derivative. ”

“ Land reptiles abounded, including species of the pterodactyle of the preceding age—tortoises, trionyces, crocodilians—and the pliosaurus, a creature which appears to have formed a link between the plesiosaurus and the crocodile. We know of at least six species of the flying saurian, the pterodactyle, in this formation.
Now, for the first time, we find remains of insects, an order of animals not well calculated for fossil preservation, and which are therefore amongst the rarest of the animal tribes found in rocks, though they are the most numerous of all living families. ”

“ Imagine one of these monstrous animals, a plesiosaurus, some sixteen or twenty feet long, 192with a small wedge-shaped crocodilian head, a long, arched, serpent-like neck, a short compact body, provided with four large and powerful paddles, almost developed into hands; an animal not covered with brilliant scales, but with a black slimy skin. ”

“ A writer in the Times of November 2, 1848, under the signature F. G. S., pointed out how many of the external characters of the creature seen from the Dædalus corresponded with the belief that it was a long-necked plesiosaurus. “Geologists,” he said, “are agreed in the inference that the plesiosauri carried their necks, which must have resembled the bodies of serpents, above the water, while their propulsion was effected by large paddles working beneath, the short but stout tail acting the part of a rudder.... In the letter and drawing of Captain M’Quhæ ... we have ... ”

“ The large Enaliosaurians are well represented by some fine specimens of Ichthyosaurus and Plesiosaurus; the P. megacephalus in the Museum at Warwick being nearly entire, measuring 14 feet 4 inches in length. Large masses of driftwood and a few fronds of ferns are sometimes met with. But perhaps the most interesting and remarkable fossils are the insects. Twenty-four families and genera were determined more than twenty years ago, since which time many important additions have been made. The Coleoptera and Neuroptera are most numerous. Small beetles are not unfrequently found entire. ”

“ Edward Newman advanced the opinion that the closest affinities of the latter would be found to be with the Enaliosauria, or marine lizards, whose [Pg 98] fossil remains are so abundant in the oolite and the lias. This view has also been taken by other writers, and emphatically by Mr. Gosse. Neither he nor Mr. Newman insist that the "great unknown" must be the Plesiosaurus itself. Mr. Gosse says, "I should not look for any species, scarcely even any genus, to be perpetuated from the oolitic period to the present. ”

“ 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.” ”

“ We may add, as further examples, the names of the various animals of which a knowledge has been acquired from the remains of them which exist in various strata, and which have been reconstructed by Cuvier and his successors. Such are the Palæotherium, the Anoplotherium, the Megatherium, the Dinotherium, the Chirotherium, the Megalichthys, the Mastodon, the Ichthyosaurus, the Plesiosaurus, the Pterodactylus. To these others are every year added; as, for instance, very recently, the Toxodon, Zeuglodon, and Phascolotherium of Mr. Owen, and the Thylacotherium of M. Valenciennes. ”

“ Physiography (fiz-e-ŏg ́rȧ-fy̆) .—The science which treats of the earth’s exterior physical features, climate, life, etc., and of the physical movements or changes on the earth’s surface, as the currents of the atmosphere and ocean, the secular variations in heat, moisture, magnetism, etc.; physical geography.
Plesiosaurus (plē-zi-ō-saw ́rus) .—An oolithic reptile with crocodile-like head, known by fossil remains, chiefly vertebræ, found in lias and oolitic rocks, named from its fossil remains being found near those of the ichthyosaurus. ”

“ Would the plesiosaurus, if he had been gifted with reasoning power, have been able to do such battle for his race that they would have survived those changes and chances which have certainly swept such creatures from existence P Without speculating on such a question, we may, nevertheless, believe that intelligence can sometimes confer on the species which possesses it a degree of pliancy in accommodating itself to altered conditions of the environment superior to that enjoyed by organisms without intellectual power. ”

“ 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 ”

“ The fourth (I. intermedius) , is, as its name implies, intermediate between the last species and the common, with respect to the form of its teeth. The two latter species do not attain half the size of the two first.
The plesiosaurus, discovered by Mr Conybeare, must have appeared 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 [257] vertebræ had more of the forms and articulations of the lizards ”

“ The latter animal had an extremely long neck and small head, with teeth like those of the crocodile, and paddles analogous to those of the Ichthyosaurus, but larger. It is supposed to have lived in shallow seas and estuaries, and to have breathed air like the Ichthyosaur and our modern cetacea. [6] Some of the reptiles above mentioned were of formidable dimensions. One specimen of Ichthyosaurus platydon, from the Lias at Lyme, now in the British Museum, must have belonged to an animal more than 24 feet in length; and there are species of Plesiosaurus which measure from 18 to 20 feet in length. ”

“ Middle Eocene. Crocodiles, Chelonians, Serpents.
Horsham, Sussex. Wealden; quarries in the vicinity. Hylæosaurus, Iguanodon, Goniopholis, Turtles, &c.
Ilminster. Upper Lias. Ichthyosaurus, Teleosaurus.
Kyson, Suffolk. Eocene. Serpent, Lizard.
Leamington. New Red. Labyrinthodon.
Lewes. Chalk. Vertebra; of Mosasaurus or Leiodon.
Lyme Regis. Lias. Pterodactyles, Ichthyosauri, and Plesiosauri in abundance.
Maidstone. Lower Green Sand; quarries near the town; particularly Mr. Bensted’s "Iguanodon quarry." Iguanodon, Plesiosaurus, Polyptychodon, Fresh-water Tortoise.
Malton. Oolite. Megalosaurus. ”

“ The Plesiosaur, on the contrary, was fitted for comparatively still and shallow waters; swimming near the surface with its graceful neck curving aloft, it could dart at the smaller fishes on the surface, or stretch its long neck downward in search of those near the bottom. The Ichthyosaurs rolled like porpoises in the surf of the Liassic coral reefs and the waves beyond; the Plesiosaurs careered gracefully in the quiet waters within. Both had their beginning at the same time in the earlier Mesozoic, and both found a common and final grave in its later sediments. ”

“ Cope erred in most of the distinctive characters that he assigned to the genus Elasmosaurus, but was correct in an important one,—the length of the neck. We shall see that in all the known species assigned to Elasmosaurus, of which this part of the skeleton is known, the neck is very long, and that all of its vertebræ, save the most posterior ones, are longer than broad. Cimoliasaurus is, therefore, a relatively short-necked plesiosaur, though not so short as in the genus Polycotylus. ”

“ 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. ”