Xenarthra (Anteaters, Sloths and Armadillos).
As to the Edentata, it is still a matter of uncertainty whether the pangolins (Pholidota) and the ant-bears (Tubulidentata) are rightly referred to an order typically represented by the sloths, anteaters, and armadillos of South and Central America, or whether the two first-named groups have any close relationship with one another.
(X 215-.) known as ground-sloths, and occupy a position intermediate between the sloths and the ant-eater: their skulls being of the type of the former, while their limbs and vertebrae conform in structure to those of the latter.
Unlike sloths, the megatherium has seven cervical vertebrae; and the spines of all the trunk-vertebrae incline backwards.
For certain small ground-sloths from Patagonia with Megatherium- like teeth, see MYLODON.
A cursory inspection of the bird, which is not unfrequently brought alive to Europe, its size, and its enormous bill and talons, at once suggest the vast powers of destruction imputed to it, and are enough to account for the stories told of its ravages on mammals - sloths, fawns, peccaries and spidermonkeys.
The mylodons belong to the group of ground-sloths, and are generally included in the family Megatheriidae, although sometimes made the type of a separate family.
The remains, which include not only the skeleton and skin, but likewise the droppings, were found buried in grass which appears to have been chopped up by man, and it thus seems not only evident that these ground-sloths dwelt in the cave, but that there is a considerable probability of their having been kept there in a semi-domesticated state by the early human inhabitants of Patagonia.
Scelidotherium is another genus of large South American Pleistocene ground-sloths, characterized, among other features, by the elongation and slenderness of the skull, which thus makes a decided approximation to the anteater type, although retaining the full series of cheek-teeth, which were, of course, essential to an herbivorous animal.
Be this as it may, the North American mammals described as Moropus and Morotherium, in the belief that they were ground-sloths, are really referable to the ungulate group Ancylopoda.
From their extremely slow movements and lethargic habits in the daytime these weird little creatures are commonly called sloths by Anglo-Indians.
Although a few of the Pleistocene ground-sloths, such as Nothropus and Nothrotherium (= Coelodon), were of comparatively small size, in the Santa Cruz beds of Patagonia few of the representatives of the family much exceeded a modern sloth in size.
By many palaeontologists a group of North American Lower Tertiary mammals, known as Ganodonta, has been regarded as representing the ancestral stock of the ground-sloths and those of other South American edentates; but according to Professor W.