MESOZOIC TIME CRETACEOUS. 



863 



Daptinus, etc. Ganoids were numerous, both, of Cestraciont Sharks and of 

 Squalodonts, the latter being represented by species of the genera Carcharias, 

 Lamna, Oxyrhina, Odontaspis, Otodus, etc. 



2. Reptiles. — The Wealden of England, a region of great marshes and 

 lakes, and the beginning of the Cretaceous, has afforded remains of 30 or 

 more species of Dinosaurians, Crocodilians, and Plesiosaurians. The number 

 is very large even for an area of 20,000 square miles (100 miles by 200). But 

 these Reptiles may not all have been cotemporaries ; yet the period wsiS 

 not so long but that one of the Iguanodons that existed in the Lower Weal- 

 den continued on into the Lower Greensand. Moreover, the species known 

 may not be a fourth of those that existed in the region during the Wealden 

 epoch. They included Dinosaurs of nearly all the subdivisions: the Her- 

 bivorous Morosaurids, as Morosaurns (Pelorosaurus) Becklesii, Cetiosaurus 

 brevis; Stegosaurids, as Hylceosaurus Oweni and Polacantlius Foxi; Ornitho- 

 poda, as Iguanodon Bernissartensis, 33 feet long, I. MantelU 20 feet long, 



1465 



Dinosaur. — Fig. 1464, Iguanodon Bernissartensis (x |). Uollo. 1465, I. ManteUi, tootli, natural size. Mante',1. 



HypsilopJiodon Foxi ; Carnivorous Dinosaurs, as Megalosaurus Dunkeri. 

 And with these and other Dinosaurs, there were some Crocodilians, a 

 Plesiosaurus, Chelonians, and several species of Pterosaurs. 



The skull of an Iguanodon, from the Wealden of Belgium, is represented 

 in Fig. 1464, and a tooth, full size, of I. MantelU, from the Wealden, in Fig. 

 1465. The foot, which is over 41- feet long, has the three-toed characteristic 

 of the Ornithopods. The genus was named from a resemblance in the teeth 

 to those of the Iguana. Among the Pterosaurs, the genus Ornithostoma of 

 Seeley includes a toothless species from the Cambridge Greensand, related to 

 Pteranodon of America. 



After the Wealden, Reptiles were less numerous. But both Herbivorous 

 and Carnivorous Dinosaurs continued. The carnivorous AcanthopJwlis 



