SOME EXTINCT ARGENTINE MAMMALS gi 
if, indeed, he ever succeeded in doing so. That man did 
exist with the later glyptodons, or those which flourished 
during the deposition of the Pampas mud, is, however, 
proved by more than one kind of evidence. For instance, 
crude drawings of these animals have been found incised 
on some of the rock surfaces of Patagonia, while in other 
cases human implements have been disinterred side by side 
with the bones and shells. Probably the empty carapaces 
of the larger members of the group were employed by the 
primitive inhabitants of Argentina as huts, and it is said 
that they are sometimes even so used at the present day 
by the Indians. That these animals were not killed off 
by any living foe—either human or otherwise—may be 
taken for granted, and we must therefore conclude that this 
result was probably due to the same general cause which 
brought about the extermination of the larger Argentine 
mammals. It may be well to mention that, although some 
of the living armadillos are carnivorous, it is perfectly 
evident, from the structure of their teeth, that all the 
glyptodons subsisted exclusively on a vegetable diet. 
The earliest known representatives of the group occur in 
the older Tertiary beds of Patagonia, and may be designated 
pigmy glyptodons, although known scientifically as Propalaco- 
hoplophorus. These creatures, which lived side by side with 
armadillos nearly akin to existing forms, were the dwarfs 
of their race, the carapace not being more than a couple 
of feet in length. The plates of the carapace were smooth, 
and ornamented with a rosette-like sculpture, of which the 
central ring in the fore part of the shell was raised into 
a prominent boss. In the form of these plates, as well as 
in the circumstances that the tail was surrounded from base 
to tip with a series of knobbed rings, these pigmy glyptodons 
resembled the ring-tailed glyptodons of the Pampas, of which 
