60 Geology of South America. 



Piray it is merely mixed with clay ; on the elevated plateaus 

 of the Andes it still exhibits a composition analogous to what 

 it presents in the Pampas ; and on the mountains of Brazil, the 

 only difference is, that it contains pebbles. 



The fossils which it contains in these various positions are 

 of a not less uniform nature. They are solely bones of ter- 

 restrial mammifera. These bones occur in prodigious quan- 

 tity, and amply compensate in interest the absence of marine 

 remains. By observing with attention the elevated falaises 

 of the banks of the Parana formed by the Tosca., which is 

 the loam in its most normal and most developed form, 

 various portions of skeletons of large animals are seen pro- 

 jecting from the escarpment, exhibited, as it were, in an im- 

 mense natural museum. These bones, mistaken at first for 

 bones of giants, have struck the inhabitants of the country for 

 a long period ; and the names of many of the localities of the 

 Pampas, and of the banks of the Parana, have been derivedfrom 

 them, such as the stream of the animal, the hill of the giant, 

 &;c. At a later period. Science noticed the subject. Falkner 

 says that he found in the Pampas the shell of an animal com- 

 posed of hexagonal bones, of which each had a diameter of 

 at least an inch.* The carapace was nearly 3 yards long, and 

 resembled in every respect that of the armadillos, but of im- 

 mense proportions. As these notices leave no doubt on the 

 subject, here we have, well-ascertained, in 1770, the presence 

 in the Pampas, not only of fossil bones, but also of that cara- 



* Falkner's observations on his discovery are curious, and worthy of quotation. 

 He says : '' I myself found the shell of an animal, composed of little hexagonal 

 bones, each bone an inch in diameter at least ; and the shell was near three yards 

 over. It seemed, in all respects, except its size, to be the upper part of the shell 

 of the armadillo ; which, in these times, is not above a span in breadth. Some 

 of my companions found also, near the river Parana, an entire skeleton of a 

 monstrous alligator. I myself saw part of the vertebrae, each bone of which was 

 near four inches thick, and about six inches broad. Upon an anatomical survey 

 of the bones, I was pretty well assured, that this extraordinary increase did not 

 proceed from any acquisition of foreign matter ; as I found that the bony fibres 

 were bigger in proportion as the bones were larger. The bases of the teeth were 

 entire, though the roots were worn away, and exactly resembled in figure the 

 basis of a human tooth, and not of that of any other animal I ever saw. These things 

 are well known to all who live in tliese countries ; otherwise, I should not have 

 dared to write them." — Description of Patagonia and the adjoining i>cirt.'! of South 

 America. By Thomas Falkner; Hereford, 1774, p. 55. — Edit. 



