Part 3

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.

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.

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: 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.