require to be classified and annotated, and full weight given to the evidence which has accumulated of the presence of man upon the earth during ages long prior to the historic period, and which may have been ages of slowly progressive civilization, or perhaps cycles of alternate light and darkness, of knowledge and barbarism.
4. – Lastly, some inquiry may be made into the geographical conditions obtaining at the time of their possible existence.
It is immaterial which of these investigations is first entered upon, and it will, in fact, be more convenient to defer a portion of them until we arrive at the sections of this volume treating specifically of the different objects to which it is devoted, and to confine our attention for the present to those subjects which, from their nature, are common and in a sense prefatory to the whole subject.
I shall therefore commence with a short examination of some of the most remarkable reptilian forms which are known to have existed, and for that purpose, and to show their general relations, annex the accompanying tables, compiled from the anatomy of vertebrated animals by Professor Huxley: —
REPTILES CLASSIFIED BY HUXLEY.
The most bird-like of reptiles, the Pterosauria, appear to have possessed true powers of flight; they were provided with wings formed by an expansion of the integument, and supported by an enormous elongation of the ulnar finger of the anterior limb. The generic differences are based upon the comparative lengths of the tail, and upon the dentition. In Pterodactylus (see Fig. 2, p. 18), the tail is very short, and the jaws strong, pointed, and toothed to their anterior extremities. In Rhamphorynchus (see Fig. 8, p. 18), the tail is very long and the teeth are not continuous to the extremities of the jaws, which are produced into toothless beaks. The majority of the species are small, and they are generally considered to have been inoffensive creatures, having much the habits and insectivorous mode of living of bats. One British species, however, from the white chalk of Maidstone, measures more than sixteen feet across the outstretched wings; and other forms recently discovered by Professor Marsh in the Upper Cretaceous deposits of Kansas, attain the gigantic proportions of nearly twenty-five feet for the same measurements; and although these were devoid of teeth (thus approaching the class Aves still more closely), they could hardly fail, from their magnitude and powers of flight, to have been formidable, and must, with their weird aspects, and long outstretched necks and pointed heads, have been at least sufficiently alarming.
We need go no farther than these in search of creatures which would realise the popular notion of the winged dragon.
The harmless little flying lizards, belonging to the genus Draco, abounding in the East Indian archipelago, which have many of their posterior ribs prolonged into an expansion of the integument, unconnected with the limbs, and have a limited and parachute-like flight, need only the element of size, to render them also sufficiently to be dreaded, and capable of rivalling the Pterodactyls in suggesting the general idea of the same monster.
It is, however, when we pass to some of the other groups, that we find ourselves in the presence of forms so vast and terrible, as to more than realise the most exaggerated impression of reptilian power and ferocity which the florid imagination of man can conceive.
We have long been acquainted with numerous gigantic terrestrial Saurians, ranging throughout the whole of the Mesozoic formations, such as Iguanodon (characteristic of the Wealden), Megalosaurus (Great Saurian), and Hylæosaurus (Forest Saurian), huge bulky creatures, the last of which, at least, was protected by dermal armour partially produced into prodigious spines; as well as with remarkable forms essentially marine, such as Icthyosaurus (Fish-like Saurian), Plesiosaurus, &c., adapted to an oceanic existence and propelling themselves by means of paddles. The latter, it may be remarked, was furnished with a long slender swan-like neck, which, carried above the surface of the water, would present the appearance of the anterior portion of a serpent.
To the related land forms the collective term Dinosauria (from δεινός “terrible”) has been applied, in signification of the power which their structure and magnitude imply that they possessed; and to the others that of Enaliosauria, as expressive of their adaptation to a maritime existence. Yet, wonderful to relate, those creatures which have for so many years commanded our admiration fade into insignificance in comparison with others which are proved, by the discoveries of the last few years, to have existed abundantly upon, or near to, the American continent during the Cretaceous and Jurassic periods, by which they are surpassed, in point of magnitude, as much as they themselves exceed the mass of the larger Vertebrata.
Take, for example, those referred to by Professor Marsh in the course of an address to the American Association for the Advancement of Science, in 1877, in the following terms: – “The reptiles most characteristic of our American cretaceous strata are the Mososauria, a group with very few representatives in other parts of the world. In our cretaceous seas they rule supreme, as their numbers, size, and carnivorous habits enabled them to easily vanquish all rivals. Some were at least sixty feet in length, and the smallest ten or twelve. In the inland cretaceous sea from which the Rocky Mountains were beginning to emerge, these ancient ‘sea-serpents’ abounded, and many were entombed in its muddy bottom; on one occasion, as I rode through a valley washed out of this old ocean-bed, I saw no less than seven different skeletons of these monsters in sight at once. The Mososauria were essentially swimming lizards with four well-developed paddles, and they had little affinity with modern serpents, to which they have been compared.”
Or, again, notice the specimens of the genus Cidastes, which are also described as veritable sea-serpents of those ancient seas, whose huge bones and almost incredible number of vertebræ show them to have attained a length of nearly two hundred feet. The remains of no less than ten of these monsters were seen by Professor Mudge, while riding through the Mauvaise Terres of Colorado, strewn upon the plains, their whitened bones bleached in the suns of centuries, and their gaping jaws armed with ferocious teeth, telling a wonderful tale of their power when alive.
The same deposits have been equally fertile in the remains of terrestrial animals of gigantic size. The Titanosaurus montanus, believed to have been herbivorous, is estimated to have reached fifty or sixty feet in length; while other Dinosaurians of still more gigantic proportions, from the Jurassic beds of the Rocky Mountains, have been described by Professor Marsh. Among the discovered remains of Atlantosaurus immanis is a femur over six feet in length, and it is estimated from a comparison of this specimen with the same bone in living reptiles that this species, if similar in proportions to the crocodile, would have been over one hundred feet in length.
But even yet the limit has not been reached, and we hear of the discovery of the remains of another form, of such Titanic proportions as to possess a thigh-bone over twelve feet in length.
Fig. 5. – Monster bones of extinct gigantic Sauriansfrom Colorado, showing relative proportionsto corresponding bone in the Crocodile (A).
(From the “Scientific American.”)
From these considerations it is evident that, on account of the dimensions usually assigned to them, no discredit can be attached to the existence of the fabulous monsters of which we shall speak hereafter; for these, in the various myths, rarely or never equal in size creatures which science shows to have existed in a comparatively recent geological age, while the quaintest conception could hardly equal the reality of yet another of the American Dinosaurs, Stegosaurus, which appears to have been herbivorous, and more or less aquatic in habit, adapted for sitting upon its hinder extremities, and protected by bony plate and numerous spines. It reached thirty feet in length. Professor Marsh considers that this, when
