2 22 POPULAR SCIENCE MONTHLY. 



An immense amount of literature has been printed on the sub- 

 ject of the Cretaceous formation and its inhabitants. Very recently 

 there have been immense advances made in the restoration of species 

 existing in Cretaceous times. This article, therefore, is in the nature 

 of scientific news, and a separation of facts from a mass of errors. In 

 looking over the works of others, one is impressed by the many 

 mistakes made by specialists, owing to imperfect skeletons and col- 

 lections. A careful study of these errors has been made in the 

 light of the latest skeletons reconstructed and the latest discoveries 

 made. 



The Kansas University, in securing three perfect type specimens 

 of three genera of mosasaurs, presents three important items of 

 scientific news. These skeletons teach us the errors and pitfalls into 

 which specialists have fallen who lacked certain parts of the skeletons 

 and filled out the gaps by aid of the imagination. Only recently the 

 country was startled by the alleged discovery of the skeleton of a 

 supposed reptile, having a length of two hundred and fifty feet. 

 The newspapers gave startling pictures of the supposed appear- 

 ance of this reptile while on earth. Professor Williston naturally 

 wanted to see this gigantic animal, the largest ever discovered. 

 On examination of its bones he saw at once that it was a whale. 

 It can safely be asserted that no animal ever attained a length 

 of two hundred and fifty feet. Perhaps as serious errors as this 

 may be found in many of our text-books and monographs, due, 

 of course, to former incomplete skeletons. The appearances of the 

 skulls, the jaws, and the teeth have been painfully distorted in like 

 publications and on charts in class rooms, and demand a thorough 

 overhauling before our youth are further taught errors. With late 

 complete discoveries, we have now exact appearances of the functions 

 of the heads from which we can derive correct views. It was for- 

 merly thought that the eyes of the mosasaurs were directed up- 

 wardly; to-day it is known that they were directed laterally, as in 

 living lizards. It has been supposed that mosasaurs attained a length 

 of one hundred feet; no skeleton has been found which would show 

 a length of more than fifty feet. The great majority of skeletons 

 taken range from sixteen to twenty feet in length. It was formerly 

 supposed that mosasaurs had the powers of running, springing, and 

 climbing on land; it is now known that they were wholly confined 

 to salt water, and merely climbed the beaches in order to lay eggs. 

 It is not an easy step from mosasaurs to modern snakes; it is an 

 utter impossibility. Professor Marsh formerly thought, and it has 

 been taught in the class rooms, that the bodies of mosasaurs had 

 bony scales ; they had skins, and were scaled throughout like modern 

 lizards and snakes. The RJiampJwrynchus has been held up to us 



