MOSASAURS. 



By S. W. WILLISTON. 



HISTORICAL. 



It is now more than a century since the first specimen of the 

 singular group of reptiles known as the Mosasaurs was dis- 

 covered, and only at the present time has our knowledge of 

 them become at all complete. No group of extinct reptiles has 

 been more abundantly represented as fossils, unless it be the 

 Dinosaurs, and in no group have more skeletons and parts of 

 skeletons been brought to light in the museums. Kansas, 

 par excellence, has been the great collecting grouud of the world 

 for these reptiles. Since first a specimen was discovered by 

 Doctor Turner, of Fort Wallace, in 1868, and taken east by 

 Leconte, to be shortly afterwards described by Cope, many hun- 

 dreds, yes thousands, of these animals have been collected. 

 Doctors Janeway and Sternberg, at Hays and Wallace, Professors 

 Marsh and Cope, in field expeditions, Professors Mudge and 

 Snow, H. A. Brous, George Cooper, Charles Sternberg, E. P. 

 West, E. W. Guild, H. T. Martin, Professor Baur, E. C. Case 

 and the writer have at different times collected for institutions 

 of America and Europe. A thousand or more specimens are 

 now in the Yale museum, collected at an expense of many 

 thousand dollars, several hundred are in the University of 

 Kansas, and other institutions of America, and others in lesser 

 number are in the museums of Munich and of Great Britain. 

 Scattered publications, based often upon fragmentary material, 

 make it difficult to obtain any connected knowledge of what the 

 forms are in Kansas. 



The present work is an endeavor to bring together clearly 

 and distinctly all the important facts about the Mosasaurs of 

 Kansas. The work has been the result of much careful study 

 8— iv (83) 



