ORDER DINOSAURIA. 



1 167 



centrum being indicative of a long and arched neck. The occur- 

 rence of a Dinosaur so far north is of extreme interest, as serving to 

 show how genera common to the Old and New Worlds may have 

 migrated from the one hemisphere to the other. 



Family Megalosaurid^e. — In this family the cervical vertebrae 

 are (when known) shorter than the dorsals, and may be either 

 amphi- or opisthoccelous ; while the dorsals often have prominent 

 ridges at the base of the arches, between which are deep pits ; the 

 vertebral centra, as in the last family, having a fusiform internal 

 cavity. In the pelvic limb of the type genus, the femur is of a re- 

 markably Crocodilian type, and is longer than the tibia. The crowns 

 of the teeth (fig. 1065) are more or less tall, and much compressed, 

 with the posterior border distinctly concave, and the serrations, 

 which are nearly at right angles to the axis of the crown, usually 

 wanting at the lower part of the anterior border. In the Lower 

 Keuper of England we meet with Palceosaurus (with which Cladyodo?i 

 of the same deposits may be identical), of which only detached teeth 

 are known. In the Upper Keuper of the Continent there occurs 

 the comparatively generalised genus Zanclodon (Teratosaurus), which 

 is not improbably iden- 

 tical with Plateosaurus, 

 in which case the latter 

 name should be adopt- 

 ed. The serrations on 

 the anterior borders of 

 the crowns of the teeth 

 continue nearly to the 

 base ; the cervical ver- 

 tebrae are amphicce- 

 lous ; there are but two 

 vertebrae in the sacrum ; 

 and the astragalus does 

 not give off a process 

 ascending on to the anterior surface of the tibia. One of the 

 species was fully as large as Megalosaurus, and the genus was 

 probably represented in the Lower Lias of Dorsetshire. The small 

 Epicampodon {Ankistrodo?i), of the Panchet stage of the Indian 

 Gondwanas, has teeth (fig. 1068) of a Megalosau.roid type, in which 

 the serrations are totally absent from the anterior border, and do 

 not extend to the base of the posterior border. 



The type genus Megalosaurus has been rendered classic through 

 the labours of the late Professors Buckland and Phillips, and affords 

 an excellent and instructive instance of the gradual restoration of 

 the skeleton of an extinct and uncouth form from more or less 

 fragmentary remains. In Europe this genus ranges from the Stones- 



1068. 



-Fragment of the mandible of Epicampodon 

 indicus ; from the Panchet beds of the Gondwanas. Three 

 times natural size. a, Lateral ; b, Posterior aspect ; c, 

 Transverse section of tooth. (After Huxley.) 



