1580 



THE AMERICAN NATURALIST 



[Vol. XLII 



manmial-like carriage. There will be little dissent from 

 the view that these animals inhabited a country in which 

 marshy lands abounded and that they passed the most of 

 their time in the vicinity of bodies of water. As to 

 weight, Marsh estimated that that of Brontosaurus was 

 more than twenty tons. Each footprint was thought to be 

 about a square yard in extent. The pressure was there- 

 fore about 1,100 pounds on each square foot of the 

 ground. What progress could such enormous animals 

 have made through morasses and along mud-depositing 

 rivers, in case they carried themselves as they are repre- 

 sented in the restorations ! Without doubt, they would 

 soon have become inextricably mired and would have 

 perished miserably. 



Osborn 16 has suggested that Camarasaurus, another 

 sauropod was accustomed to wading about in rivers 

 where the bottoms were sandy and firm. The habits of 

 Diplodocus could have differed little from those of 

 Camarasaurus. It is difficult to understand why an 

 animal whose immediate ancestors must have walked 

 about in a crocodile-like manner, an animal that was 

 stupid and probably slow of movement, an animal which 

 could by means of its long neck reach up from the bot- 

 tom many feet to the surface and from the surface many 

 feet to the bottom— why such a reptile should need to de- 

 velop the ability to walk along river bottoms like a 

 mammal. Furthermore, it seems somewhat overgener- 

 ous to impute to a reptile so many and so diverse activi- 

 ties as swimming with great facility, walking on river 

 bottoms and on the land with mammal-like gait, and on 

 occasion erecting itself on its hinder legs after the man- 

 ner of a bird, in order to crop the foliage from the tops of 

 high trees, when this reptile was sixty feet long, weighed 

 many tons, had a brain little larger than one's two thumbs 

 placed side by side, and was provided with a feeble dental 

 apparatus with which to gather food wherewith to sup- 

 port its huge body, and that food of a sort that yielded 

 little energy in proportion to its bulk. 



