THE AMERICAN MUSEUM OF NATURAL HISTORY 



skin, showing its texture, is preserved. Near-by are speci- 

 mens of Pterodactyls, or flying reptiles, and a mounted 

 specimen of a peculiar marine bird, Hesperornis regalis, 

 from the Cretaceous of Kansas. This bird, like the more 

 ancient Arch&opteryx, which is the earliest bird known, had 

 a row of small teeth in the jaws, a reminiscence of its rep- 

 tilian ancestry, but it had lost the long reptilian tail which 

 Archceopteryx still preserved. 



Immediately at the right of the entrance are the newly 

 discovered and recently mounted skeletons from the Creta- 

 ceous of Alberta, Canada, of the crested duck-bill dinosaur 

 Saurolophus, a herbivorous reptile, the helmet duck-bill 

 dinosaur Corythosaurus, with its crested head similar to 

 that of a cassowary, the horned dinosaur Monoclonius and 

 the bird-like dinosaur Ornithomimus. 



On the south side of the hall is the finest collection of 

 fossil turtles in any museum, also specimens of finback 

 lizards (Naosaurus and Dimetrodon), a specimen of Dia- 

 dectes, a reptile with a solid-roofed skull, and one of 

 Eryops, a primitive amphibian which inhabited the great 

 swamps of the coal period and was one of the earliest land 

 vertebrates. The latter represents the primitive amphibians, 

 which are regarded as the ancestors of reptiles, birds and 

 mammals as well as of the modern amphibians (frogs, 

 etc.). These and other smaller specimens in the adjoining 

 wall case are more ancient than the dinosaurs and lived at 

 the time when the coal measures of Pennsylvania were 

 being formed. 



106 



