THEROPODA 



421 



Fig. 98. — Skull of Anchisauriis 

 coelurus. x\. (After Marsh.) 

 a, Nasal fossa ; 6, antorbital. 

 c, infra-temporal, d, supra- 

 temporal, ando, orbital fossa ; 

 q, quadrate bone. 



from its foot-spoors only, which, together with other three-toed 

 spoors in the sandstone of the Connecticut valley, were originally 

 described and figured by Hitchcock as Ornithichnites (t'xi'o? = 

 track, or spoor). Some of these imprints are more than a foot, in 

 length, the right and left spoors following alternately at a dis- 

 tance of from four to six feet. In some cases the long trailing 

 tail has left a furrow behind, and the large tracks are accom- 

 panied or crossed by much smaller, and even by quite tiny 

 tracks, otherwise similar, and undoubtedly made by the young. 



Anchisaurus, from the same locality, was still Sauropodous, 

 in so far as the metatarsals are still free, with two, three, four, 

 and five phalanges on the first four 

 toes, but the fifth metatarsal is re- 

 duced, carrying a vestige of only one 

 phalanx, and the proximal tarsal bones 

 are fused with the tibia and fibula 

 respectively. Total length some seven 

 feet, of which about four belong to the 

 tail. 



Zanclodon, from the Keuper of 

 "Wiirtemberg, about ten feet long, with pentadactyle hands and 

 feet. Ischia stronger than the pubic bones, which are distally 

 much broadened. The femur is nearly three feet long, and 

 possesses a fourth trochanter. The astragalus has an ascending 

 process, and is fused with the tibia. The toes are short, strong, 

 and clawed. The shoulder-girdle and fore-limb are strong, the 

 latter well adapted to grasping. The teeth are much compressed 

 laterally, with sharp, finely serrated edges. Several allied genera 

 have been described from the Upper Trias of France and England ; 

 others from corresponding strata of India and South Africa. 



Megalosaurus, from the Trias to the Wealden in England 

 and France, with other species in Colorado and India, reached a 

 considerable size, larger than that of any other Theropoda, the 

 scapula of M. bucHandi being nearly three feet long, and the 

 femur still longer. The hind-limbs are twice as long as the 

 fore-limbs. The cervical vertebrae are short, the neck being 

 much shorter than the tail. Hands with five fingers, feet with 

 four toes. Pubic bones long and slender, with a broad sym- 

 physis. With well-developed abdominal ribs, resembling those 

 of crocodiles. 



