6 M. S. Lull — Dinosaurian Distribution. 



infra p. 31) north of India, but practically wherever dinosaurs 

 of whatever sort are found. 



The Sauropoda. 



During the Triassic, the carnivores had spread to other 

 conditions and had given rise to a new order, the Sauropoda, 

 no longer truly terrestrial, but inhabiting the bayous and 

 swamps of the numerous deltas which fringed the continental 

 shores. This change of habitat w T as far-reaching in its effects, 

 for rapid locomotion was no longer necessary and a certain 

 degeneracy resulted — whether the carnivorous ancestors had 

 attained bipedalism or whether the Sauropoda were primi- 

 tively quadrupedal I cannot say. Increase in size was accom- 

 panied by an elongation of the neck to get a greater range of 

 feeding with as little bodily movement as possible and it 

 necessitated as well a diametric change in diet, for with 

 increasing bulk, no longer finding the animal food of their 

 forbears adequate or readily obtainable, they took to an 

 herbivorous feeding habit which required but little change in 

 the mouth armament. * 



The modern Iguanidse show a certain parallelism with the 

 Sauropoda, for while the primitive diet is carnivorous (insect- 

 ivorous) " some of the most striking forms are herbivorous, e.g. 

 Iguana, Amblyrhynchus, and Basiliscus." (Gadow 1908, pp. 

 528, 533.) Moreover, one finds within the family not only 

 semi-aqnatic adaptation, but even semi-marine. The last is 

 shown by Amblyrhynchus cristatus, which " inhabits the 

 rocky and sandy strips of coast of most of the Galapagos 

 Islands, feeding on certain kinds of algae, which it has to dive 

 for, since these plants grow below tide-marks." 



The precise food of the Sauropoda is a matter of doubt. 

 Dr. Hay (1908, p. 674), in discussing that of Diplodocus, the 

 most highly specialized member of the order, sums up the 

 expressions of opinion as follows : " Hatcher suggested that 

 the teeth might have been useful in detaching from the bot- 

 toms and shores the succulent aquatic and semi-aquatic plants 

 that must have grown there in abundance. Osborn [1889, p. 

 214] says that the ' food probably consisted of some very large 

 and nutritious species of water plant. The anterior claws may 

 have been used in uprooting such plants * * * The plants 

 may have been drawn down the throat in large quantities 

 without mastication.' * * * Holland [1906, p. 240] thinks 

 that the teeth were better adapted for raking and tearing off 

 from the rocks soft masses of clinging algae than for securing 

 any other forms of vegetable food now represented in the 

 waters of the world. 



