56 WATER REPTILES OF THE PAST AND PRESENT 



least three genera of plesiosaurs are known from Kansas, Texas, 

 and Arkansas, with two or three more from the Hmestone shales 

 of Wyoming. A few specimens of armored dinosaurs, two genera 

 of ancient crocodiles, nearly the last of their kind, some marine 

 turtles, and a few vertebrae of ichthyosaurs, the last of the order 

 known anywhere in the world, are also known from the Benton 

 Cretaceous of \V}'oming. 



Continuous with the Benton limestones above in Kansas are 

 the famous beds of Niobrara chalk; perhaps no fossil deposits in 

 the world are more famous. Exposures covering hundreds of 

 square miles in western Kansas, almost pure chalk, have furnished 

 fossil-hunters during the past forty years literally thousands of 

 specimens of mosasaurs, hundreds of pterodactyls, and scores of 

 plesiosaurs and marine turtles, in addition to the famous birds with 

 teeth and countless fishes of diverse kinds. Two or three specimens 

 of spoon-billed dinosaurs have been found in these deposits, but no 

 other reptiles of any kinds. Beds of like age in Colorado and New 

 Mexico have furnished a few specimens of mosasaurs. 



From the marine beds of Fort Pierre age, next above the Nio- 

 brara in the west, have come some excellent specimens of two genera 

 of mosasaurs, three or four forms of plesiosaurs, a few pterodactyls, 

 the largest of all marine turtles, and still fewer specimens of dino- 

 saurs, in Kansas, South Dakota, Wyoming, and Montana. From 

 deposits of approximately like age in Mississippi, Alabama, and 

 New Jersey, many incomplete specimens were found years ago of 

 mosasaurs, plesiosaurs, and turtles, the last of the amphicoelian 

 crocodiles, the first of the prococlian crocodiles, and the famous 

 specimen of Hadrosaurus which served for the Hawkins restoration, 

 the first attempt of its kind. 



From the uppermost Cretaceous beds of America, the Lance, 

 Judith River, or Belly River beds as they are variously called, have 

 come the remains of a marvelous reptilian fauna. These beds may 

 be grouped together though not all contemporaneous, and there is 

 dispute about their age, some excellent paleontologists insisting 

 that the uppermost are really of Eocene age. From Colorado east 

 of Denver, from eastern Wyoming, from Montana, and especially 

 from the vicinitv of Edmonton in Canada, as also occasionallv in 



