54 WATER REPTILES OF THE PAST AND PRESENT 



The fossils from these beds occur for the most part at least in the 

 horizon called the Shinarump. Its age is usually considered to be 

 Upper Triassic, but the character of the fossils seems to indicate 

 possibly the Middle Triassic. Aside from the stereospondylian 

 amphibians, the last of the Stegocephalia, the vertebrates from this 

 horizon and these regions are chiefly Phytosauria. A few anomo- 

 donts, or what seem to be anomodonts — the only record of their 

 occurrence outside of Africa — are known from Wyoming and Utah. 

 And a single specimen from the Wind River red beds, described 

 by the writer as Dolichobrachium, may represent reptiles allied to 

 the dinosaurs. Phytosaur fossils of this horizon have been dis- 

 covered in Utah, the Wind River Mountains, and near Laramie 

 City in Wyoming; in southwestern Colorado; in western Texas; 

 and in various places in New Mexico and Arizona. Doubtless 

 when these fossiliferous beds are more thoroughly explored many 

 new and interesting reptiles will be discovered. 



Phytosaur remains, probably of about the same age as the Rocky 

 Mountain ones, have long been known from the Triassic of North 

 Carolina. From somewhat more recent Triassic deposits in Con- 

 necticut and Massachusetts, several skeletons of small carnivorous 

 dinosaurs, and various parasuchian remains have been described 

 by Marsh, Lull, and Talbot. And these beds have long been 

 famous in Massachusetts for their footprints, for the most part 

 originally referred to birds, but now pretty well known to have 

 been made by dinosaurs and amphibians. 



No vertebrate fossils of Lower or even Middle Jurassic age are 

 known from North America. From the Baptanodon beds of Wyo- 

 ming, limestones of about two hundred feet in thickness, four 

 genera of plesiosaurs, the very peculiar ichthyosaur from which 

 the beds take their name, and a few bones of an ancient crocodile 

 are known. 



Immediately overlying the Baptanodon beds, the Morrison beds, 

 of from two hundred to four hundred feet in thickness, probably 

 of Uppermost Jurassic and Lowermost Cretaceous age, have yielded 

 an exceedingly rich vertebrate fauna, consisting chiefly of dinosaurs. 

 Discovered first in the vicinity of Morrison, Colorado, in 1877, 

 hundreds of tons of bones have been collected from these beds for 



