The World Before the Deluge
409
POST-PLIOCENE PERIOD.
occupied in burrowing under the earth, seeking for roots, and which would consequently rarely change its place? What need had it of agility to fly from its enemies, when it could overthrow the Crocodile with a sweep of its tail? Secure from the attacks of other animals,
Fig. i83.— Megatherium restored.
this robust herbivorous creature, of which Figure 188 is a restoration, must have lived peacefully and respected in the solitary pampas of America. The immediate cause of the extinction of the Megatherium is, probably, to be found in causes which are still in operation in South America. The period between the years 1827 and 1830 is called
4IO THE WORLD BEFORE THE DELUGE.
the "gran seco," or the great drought, in South America; and according to Darwin, the loss of cattle in the province of Buenos Ayres alone was calculated at 1,000,000 head. One proprietor at San Pedro, in the middle of the finest pasture-country, had lost 20,000 cattle previously to those years. " I was informed by an eyewitness,'' he adds, " that the cattle, in herds of thousands, rushed into the Parana, and, being exhausted by hunger, they were unable to crawl up the muddy banks, and thus were drowned. The arm of the river which runs by San Pedro was so full of putrid carcases, that the master of a vessel told me that the smell rendered it quite impassable. All the small rivers became highly saline, and this caused the death of vast numbers in particular spots; for when an animal drinks of such water it does not recover. Azara describes the fury of the wild horses on a similar occasion: rushing into the marshes, those which arrived first being overwhelmed and crushed
by those which followed."'" The upright position in which the various specimens of Megatheria were found indicates some such cause of death; as if the ponderous animal, approaching the banks of the river, when shrunk within its banks, had been bogged in soft mud, sufliciently adhesive to hold it there till it perished.
Like the Megatherium, the Mylodon closely resembled the Sloth, and it belonged exclusively to the New World. Smaller than the Megatherium, it differed from it chiefly in the form of the teeth. These organs presented only molars with smooth surfaces, indicating that the animal fed on vegetables, probably the leaves and tender buds of trees. As the Mylodon presents at once hoofs and claws on each foot, it has been thought that it formed the link between the hoofed, or ungulated animals and the Edentates. Three species are known, which lived in the pampas of Buenos Ayres.
In consequence of some hints given by the illustrious Washington, Mr. Jefferson, one of his successors as President of the United States, discovered, in a cavern of Western Virginia, the bones of a species of gigantic Sloth, which he pronounced to be the remains of some carnivorous animal. They consisted of a femur, a humerus, an ulna, and three claws, with half a dozen other bones of the foot. These bones Mr. Jefferson believed to be analogous to those of the lion. Cuvier saw at once the true analogies of the animal. The bones were the remains of a species of gigantic Sloth; the complete skeleton of which was subsequendy discovered in the Mississippi, in such a perfect state of preservation that the cartilages, still adhering
- "Journal of Researches," &c., 2nd ed., p. 133. Charles Darwin.
POST-PLIOCENE PERIOD.
to the bones, were not decomposed. Jefferson called this species the Megalonyx. It resembled in many respects the Sloth. Its size was that of the largest ox; the muzzle was pointed; the jaws were armed with cylindrical teeth; the anterior limbs much longer than the pos-411 terior the; articulation of the foot oblique to the leg; two great toes, short, and armed with long and very powerful claws; the index fmger
Fig. 189, — Mylodon robustus.
more slender, and armed also with a less powerful claw; the taif strong and solid: such were the salient points of the organisation of the Megalonyx, whose form was a little slighter than that of the Megatherium. The country in which the Megatherium has been found is describecF by Mr. Darwin as belonging to the great Pampean fomiation, which consists partly of a reddish clay and in part of a highly calcareous^ marly rock. Near the coast there are some plains formed from the
THE WORLD BEFORE THE DELUGE.
412
•wreck of the upper plain, and from mud, gravel, and sand thrown up "'by the sea during the slow elevation of the land, as shown by the raised beds of recent shells. At Punta Alta there is a highly-interesting section of one of the later-formed little plains, in which many remains of these gigantic land-animals have been found. These were, says Mr. Darwin:— " First, parts of three heads and other bones of the Megatherium, the huge dimensions of which are expressed by its name. Secondly, the Alegalonyx, a great allied animal. Thirdly, the ScelidotJwhim, also an allied animal, of which I obtained a nearly perfect skeleton: it must have been as large as a rhinoceros; in the structure of its head it comes, according to Professor Owen, nearest to the Cape Anteater, but in some other respects it approaches to the Armadilloes. Fourthly, the Mylodon Darwinii a closely related genus, of little inferior size. Fifthly, another gigantic edental quadruped. Sixthly, a large animal with an osseous coat, in compart-ments, very like that of an armadillo. Lower jaw of the Mylodon. Seventhly, an extinct kind of horse. Eighthly, a tooth of a pachydermatous animal, probably the same with the Macrauchenia, a huge beast with a long neck like a camel. Lastly, the Toxodon, perhaps one of the ^strangest animals ever discovered; in size it equalled a]i Elephant or Megatherium, but the structure of its teeth, as Professor Owen states, proves indisputably that it was intimately related to the Gnawers, the order which, at the present day, includes most of the smallest quadrupeds; in many details it is allied to the pachydermata; judging from the position of its eyes, ears, and nostrils, it was probably aquatic, Jike the Dugong and Manatee, to which it is aUied. How wonderfully are the different orders — at the present time so well separated — Wended together in different points in the structure of thcToxodon!"*
The remains on which our knowledge of the Scelidotheriiim is
■Journal of Researches," &c., by Charles Darwin, p. 8i.
founded include the cranium, which is nearly entire, with the teeth and part of the os hyoides, seven cervical, eight dorsal, and five-sacral vertebras, both the scapulae, and some other bones. The remains of the cranium indicate that its general form was an elongated slender compressed cone, beginning behind by a flattened vertical base, expanding slightly to the cheek-bone, and thence contracting: to the anterior extremity. All these parts were discovered in their natural relative positions, indicating, as Mr. Darwin observes, that the gravelly formation in which they were discovered had not beeii disturbed since its deposition. ^
Fig. igi.— Skull of Scelidotherium.
The lower jaw-bone of Mylodofi, which Mr. Darwin discovered at the base of the cliff called Punta Alta, in Northern Patagonia, had the teeth entire on both sides; they are implanted in deep sockets, and only about one-sixth of the last molar projects above the alveolus, but the proportion of the exposed part increases gradually in the inner teeth (Fig. 191). " The habits of life of these Megatheroid animals were a complete puzzle to naturalists, until Professor Owen solved the problem with remarkable ingenuity. The teeth indicate, by their simple structure, that these Megatheroid animals lived on vegetable food, and probably on the leaves and small twigs of trees; their ponderous forms and great strong curved claws seem so little adapted for locomotion, that some eminent naturalists have actually believed that, like the Sloths, to which they are intimately related, they sub-sisted by climbing back downwards, on trees, and feeding on the leaves. It was a bold, not to say preposterous idea to conceive even antedulivian trees ^vith branches strong enough to bear animals as large as elephants. Professor Owen, with far more pro
bability, believes that, instead of climbing on the trees, they pulled the branches down to them, and tore up the smaller ones by the roots, and so fed on the leaves. The colossal breadth and weight of their hinder quarters, which can hardly be imagined without
Fig. 192. — DInornis, and Bos.
having been seen, become, on this view, of obvious service instead of being an encumbrance; their apparent clumsiness disappears. With their great tails and their huge heels firmly fixed like a tripod in the ground, they could freely exert the full force of their most powerful arms and great claws. The Alylodon^ moreover, was furnished with a long extensile tongue, like that of the giraffe, which by
XXVIII.—Ideal European Landscape in the Quaternary Epoch.
POST-PLIOCENE PERIOD. 41/
one of those beautiful provisions of Nature, thus reaches, with the
aid of its long neck, its leafy food."*
Two gigantic birds seem to have lived in New Zealand during the Quaternary epoch. The Dinomis, which, if we may judge from the tibia, which is upwards of three feet long, and from its eggs, which are much larger than those of the Ostrich, must have been of most extraordinary size for a bird. In Fig. 192 an attempt is made to restore this fearfully great bird, the Dino7'7iis. As to the Epiornis, its eggs only have been found.
On the opposite page (Plate XXVIII.) an attempt is made to represent the appearance of Europe during the epoch we have under consideration. The Bear is seated at the mouth of its den — the cave (thus reminding us of the origin of its name of Ursus spelceus), where it gnaws the bones of the Elephant. Above the cavern the Hym7ia spelcca looks out, with savage eye, for the moment when it will be prudent to dispute possession of these remains with its formidable rival. The great Wood-stag, with other great animals of the epoch, occupies the farthest shore of a small lake, where some small hills rise out of a valley crowned with the trees and shrubs of the period. Mountains, recently upheaved, rise on the distant horizon, covered with a mantle of frozen snow, reminding us that the glacial period is approaching, and has already begun to manifest itself.
All these fossil bones, belonging to the great Mammalia which we have been describing, are found in the Quaternary formation; but the most abundant of all are those of the Elephant and the Horse. The extreme profusion of the bones of the Mammoth, crowded into the more recently formed deposits of the globe, is only surpassed by the prodigious quantity of the bones of the Horse which are buried in the same beds. The singular abundance of the remains of these two animals proves that, during the Quaternary epoch, the earth gave nourishment to immense herds of the Horse and the Elephant. It is probable that from one pole to the other, from the equator to the two extremities of the axis of the globe, the earth must have formed a vast and boundless prairie, while an immense carpet of verdure covered its whole surface; ai\d such abundant pastures would be absolutely necessary to sustain these prodigious numbers of herbivorous animals of great size. The mind can scarcely realise the immense and verdant plains of this earlier world, animated by the presence of an infinity of such