the
Megathere accords with the supposition that it obtained its food
in this way. Similar habits were followed by the allied _Mylodon_
(fig. 261), another of the great "Ground-Sloths," which inhabited
South America during the Post-Pliocene period. In most respects,
the _Mylodon_ is very like the Megathere; but the crowns of the
molar teeth are flat instead of being ridged. The nearly-related
genus _Megalonyx_, unlike the Megathere, but like the Mylodon,
extended its range northwards as far as the United States.

[Illustration: Fig. 260.--_Megatherium Cuvieri_. Post-Pliocene,
South America.]

Just as the Sloths of the present day were formerly represented
in the same geographical area by the gigantic Megatheroids, so
the little banded and cuirassed Armadillos of South America were
formerly represented by gigantic species, constituting the genus
_Glyptodon_. The _Glyptodons_ (fig. 262) differed from the living
Armadillos in having no bands in their armour, so that they must
have been unable to roll themselves up. It is rare at the present
day to meet with any Armadillo over two or three feet in length;
but the length of the _Glyptodon clavipes_, from the tip of the
snout to the end of the tail, was more than nine feet.

[Illustration: Fig. 261.--Skeleton of _Mylodon robustus_.
Post-Pliocene, South America.]

[Illustration: Fig. 262.--Skeleton of _Glyptodon clavipes_.
Post-Pliocene, South America.]

There are no canine or incisor teeth in the _Glyptodon_, but
there are eight molars on each side of each jaw, and the crowns
of these are fluted and almost trilobed. The head is covered
by a helmet of bony plates, and the trunk was defended by an
armour of almost hexagonal bony pieces united by sutures, and
exhibiting special patterns of sculpturing in each species. The
tail was also defended by a similar armour, and the vertebrae were
mostly fused together so as to form a cylindrical bony rod. In
addition to the above-mentioned forms, a number of other Edentate
animals have been discovered by the researches of M. Lund in
the Post-Pliocene deposits of the Brazilian bone-caves. Amongst
these are true Ant-eaters, Armadillos, and Sloths, many of them
of gigantic size, and all specifically or generically distinct
from existing forms.

Passing over the aquatic orders of the _Sirenians_ and _Cetaceans_,
we come next to the great group of the Hoofed Quadrupeds, the
remains of which are very abundant in Post-Pliocene deposits