434 



STEATIGRAPHICAL GEOLOGY 



Of Upper Jurassic reptiles, Cimoliosaurus, Peloneustes, Pliosa urus, 

 Ichthyosaurus, with the crocodiles Teleosaurus, Steneosaurus, Dako- 

 saums, and Goniopholis were the chief aquatic genera. Ceteosaurus, 

 Gigantosaurus, Iguanodon, Omosaurus, and Cryptosaurus were ter- 

 restrial Dinosaurs, and in America other remarkable genera, Bronto- 

 saurus and Atlantosaurus, both of enormous size, have been found. 



Fig. 143. GROUP OF OXFORDIAN FOSSILS. 



a. Gryphsea dilatata. d. Cosmoceras Jason. 



1>. Anatina undnlata. e. Cardioceras excavatum. 



c. Dicroloma compositum. /. Belemnites hastatus. 



g. Leptolepis inacrophthalmus. 



Of Pterosauria species of Pterodactylus, Scaphognathus (Fig. 142), 

 and Rhamphorhynchus were prevalent. 



That small Mammalia existed throughout the Jurassic period on 

 terrestrial surfaces there can be little doubt, but their remains are 

 not found in purely marine deposits. The Purbeck Beds, however, 

 have yielded no fewer than twelve genera and twenty species of 

 marsupials, the most important genera being Playiaulax, Belodon, 

 .Spalacotherium, Triconodon, Stylodon, and Amblotherium. 



Birds also of a primitive kind had now come into existence, 



