V 
EXTINCT QUADRUPEDS 
87 
The remains of these nine great quadrupeds and many 
detached bones were found embedded on the beach, within the 
space of about 200 yards square. It is a remarkable circum¬ 
stance that so many different species should be found together ; 
and it proves how numerous in kind the ancient inhabitants of 
this country must have been. At the distance of about thirty 
miles from P. Alta, in a cliff of red earth, I found several 
fragments of bones, some of large size. Among them were the 
teeth of a gnawer, equalling in size and closely resembling 
those of the Capybara, whose habits have been described ; and 
therefore, probably, an aquatic animal. There was also part of 
the head of a Ctenomys ; the species being different from the 
Tucutuco, but with a close general resemblance. The red 
earth, like that of the Pampas, in which these remains were 
embedded, contains, according to Professor Ehrenberg, eight 
fresh-water and one salt-water infusorial animalcule ; therefore, 
probably, it was an estuary deposit. 
The remains at Punta Alta were embedded in stratified 
gravel and reddish mud, just such as the sea might now wash 
up on a shallow bank. They were associated with twenty- 
three species of shells, of which thirteen are recent and four 
others very closely related to recent forms. 1 From the bones 
of the Scelidotherium, including even the kneecap, being 
entombed in their proper relative positions, 2 and from the 
osseous armour of the great armadillo-like animal being so well 
preserved, together with the bones of one of its legs, we may 
feel assured that these remains were fresh and united by their 
ligaments, when deposited in the gravel together with the shells. 
Hence we have good evidence that the above enumerated 
gigantic quadrupeds, more different from those of the present 
day than the oldest of the tertiary quadrupeds of Europe, lived 
whilst the sea was peopled with most of its present inhabitants ; 
and we have confirmed that remarkable law so often insisted 
on by Mr. Lyell, namely, that the “ longevity of the species in 
1 Since this was written, M. Alcide d’Orbigny has examined these shells, and 
pronounces them all to be recent. 
2 M. Aug. Bravard has described, in a Spanish work (Observaciones Geologicas, 
1857), this district, and he believes that the bones of the extinct mammals were 
washed out of the underlying Pampean deposit, and subsequently became embedded 
with the still existing shells ; but I am not convinced by his remarks. M. Bravard 
believes that the whole enormous Pampean deposit is a sub-aerial formation, like 
sand-dunes : this seems to me to be an untenable doctrine. 
