The edentates are a rather primitive group of mammals which are
represented by such living forms as the anteaters, tree sloths, and
armadillos. Members of this group were common in the southern part of
the United States in Pleistocene and Pliocene time, and fossil edentates
have been reported from rocks of this age in Texas. One such form was
_Mylodon_ (Pl. 46), one of the extinct giant ground sloths. These huge
sloths were quite heavy and some of them stood as much as 15 feet tall;
these great creatures were the forerunners of the modern tree sloths of
South America. The mounted skeleton of one of these giant ground sloths
is displayed in the Texas Memorial Museum.
[Illustration: Plate 46
CENOZOIC MAMMALS]
ENTELODONT × ¹/₃₅
GLYPTODON × ¹/₅₀
MYLODON × ¹/₉₀
Another interesting representative of this order was the glyptodont.
These peculiar mammals, which were ancestral to the present-day
armadillos, developed at about the same time as the ground sloths.
_Glyptodon_ (Pl. 46), a typical glyptodont that has been reported from
the Pleistocene of Texas, is quite characteristic of this group. This
armadillo-like beast had a solid turtle-like shell that in some forms
was as much as 4 feet high. From the front of the bone capped head to
the tip of its tail, a large individual might be as much as 15 feet
long. The thick heavy tail was protected by a series of bony rings, and
in some species the end of the tail was developed into a bony heavily
spiked club. The _carapace_ (hard outer shell) of a large glyptodont is
mounted at the Texas Memorial Museum.