INTRODUCTION 9 



New discoveries continually produce new conditions; there is nothing 

 more o])structive tlian reverence for old ideas and systems which have 

 outlived their usefulness. In observation the old motto seems to have 

 been de minimis non curat lex, to the effect that one can afford to pass 

 over the minute; at the present time we cannot be too exact in the ob- 

 servation of the minute. The vertebrate paleontologist must follow the 

 precise methods long ago introduced by Waagen (1869) among the in- 

 vertebrates. Every rudiment of a cusp on a tooth, or facet, or articulating 

 surface on a bone has its value, not as a sign-post on which to hang a new 

 species, but as suggestive of the dawn of some new character, or the instru- 

 ment of some function or relationship; the old bird's-eye methods of 

 comparison, which found no difference between the grinding teeth of a 

 rhinoceros and of a lophiodon, are of no service when we are called upon 

 to distinguish between many lines of ancient mammals crowding in among 

 the ancestors of existing mammals. Such methods of precise observa- 

 tion we owe largely to the influence of Riitimeyer and Kowalevsky. 



Influence of American Discovery 



The first mammalian remains from the Badlands of the Great Plains 

 of the West, east of the Rocky Mountains, consisted of fragments of the 

 lower jaw of the enormous quadruped, later called Titanotherium, which 

 was described by Dr. Hiram A. Prout of St. Louis in the American Journal 

 of Science in 1846. We now know that this specimen was of Lower Oli- 

 gocene Age. Travelers connected with the American Fur Company 

 brought other specimens East in 1846 and 1847. In 1849 Dr. David Dale 

 Owen and Dr. John Evans explored the "Mauvaises terres," and brought 

 back collections which were first described in Owen's Geological Report 

 of 1852. This attracted a great deal of attention, and led to the prolonged 

 explorations of Ferdinand Vandeveer Hayden (1829-1887) and Fielding 

 Bradford Meek (1817-1876) between 1853 and 1866 of the whole region 

 of Nebraska and Dakota. The collections of mammalian remains, prac- 

 tically all of which were new to science, fell into the able hands of Dr. 

 Joseph Leidy of Philadelphia. In 1852 he published his first volume, 

 entitled "The Ancient Fauna of Nebraska," ^ and in 1869 appeared his 

 great work "The Extinct Mammalian Fauna of Dakota and Nebraska," - 

 which closed with a synopsis of all fossil mammalian remains of North 

 America kno\vn at that time. This monumental work laid the broad 

 foundations of modern study and must still be considered one of the great- 

 est single contributions to the mammalian palaeontology of North America. 



' Leidy, The Ancient Fauna of Nebraska, or a Description of Remains of Extinct Mam- 

 malia and Chelonia. Smithson. Contrih. to Knowl., Vol. VI, 1852. 



^ Leidy, J., The Extinct Mammalian Fauna of Dakota and Nebraska, including an 

 Account of some Allied Forms from other Localities, together with a Synopsis of the Mam- 

 malian Remains of North America. Philadelphia, 1869. 



