HABITS OF THE ^lEGALOSAURID^ 457 



The American Morrison genus Ceratosaurus lias also been recognized 

 (the evidence is given elsewhere) as a coelnrosaurian, but resembling in 

 some respects the Megalosauridae. 



Habits of the Megalosaurid^ 



I have discussed at length the phylogenetic and biological features in 

 the paper mentioned above. For the former I give only a diagram and 

 for the latter the following results : 



The small fore limb of the Megalosauridse, especially of the latest 

 forms, and of the Deinodontidae, with the large manus and enormous 

 claws, which was no longer able to reach the mouth, could not have func- 

 tioned in holding the prey or in tearing it to pieces. The hind limb, 

 together with the mouth, must have been used for this purpose. The 

 fore limb was doubtless useful in the killing of victims, in rivalry fights, 

 in sexual activity, and in hatching and brooding the eggs and young. 

 The relatively large fore limb of most of the Coelurosauria, with its 

 manus highly specialized on a primitive base, certainly served as a well 

 developed grasping organ. It is supposed that the habits of Ornitlio- 

 mimus (Struthiomimus) , the toothless terminal member of the Coeluro- 

 sauria, were adapted to digging out small vertebrates and other animals, 

 or rather to scraping out and stealing the eggs of large reptiles which 

 were hidden in the ground. 



The opisthocoelous condition of the anterior presacral vertebrae of the 

 Megalosauridae and of the Deinodontid^ is explained as an adaptation 

 to the habit of tearing the prey to pieces. The victim was probably held 

 with the hind foot of the captor, the iiesh was seized with its teeth and 

 pulled off, upward and foreward, and in so doing the vertebral column 

 had to double up and vigorously jerk upward. 



In the ccelurosaurian genus Ceratosaurus a "quasi-opisthocoelous" con- 

 dition is developed in the anterior presacral column, because it had 

 adopted rapacious habits resembling those of the MegalosauridcT. 



