THE AMERICAN NATURALIST 



[Vol. XLII 



the spaced teeth. In addition to various algae there were 

 probably other floating plants. 



The Posture of Diplodocus 

 Marsh presented no restoration of Diplodocus, but he 

 did furnish restorations of Brontosaurus; and he stated 

 that he regarded it as representing the general form and 

 proportions of the Sauropoda. In this figure Bronto- 

 saurus is shown as walking with the body high above the 

 ground and with the limbs, especially the hinder ones, 

 about as straight as they are in the elephant. 



So far as the bearing of Brontosaurus and Diplodocus 

 on their limbs is concerned, Marsh's example has been 

 almost slavishly followed ever since. No one, so far as 

 the writer knows, has ventured to defend in print a more 

 crocodilian posture. Osborn 8 grants that there is room 

 for wide differences of opinion as regards the habits and 

 means of locomotion of these gigantic animals and states 

 that some hold the opinion that on land at least these 

 reptiles had rather the attitude of the alligator. The 

 same writer says in Nature, vol. 73, 1906, p. 283, that Dr. 

 Matthew and Mr. (lid ley have maintained the latter view. 

 However, the trend of opinion seems to have been in the 

 opposite direction. Osborn 9 suggested that Diplodocus 

 might lift its fore limbs from the ground and support 

 itself on the hinder legs and the tail. This idea has 

 found expression in Knight's restoration referred to 

 above. Osborn 's general notion of Diplodocus seems, 

 however, to be that it was essentially an aquatic animal, 

 long, light-limbed, and agile, and capable of swimming 

 rapidly by means of its great tail, provided, as he 

 thought, with a vertical fin; yet occasionally going about 

 on land. Hatcher 10 opposed the view that Diplodocus 

 was aquatic; and he showed that there is no evidence of 

 the presence of a vertical fin. The compression of the 



• Science, XXII, 1905, p. 376. 



Mem. Amer. Mm. Nat. Hist., T, p. 213. 



"Mem. Carnegie Mux., TT. 1903, p. 59. 



