Department of Geology 



Research . . . 



Until October, when Mr. Bryan Patterson, Curator of Paleon- 

 tology, was called into the Army, the Division of Paleontology had 

 not been handicapped by loss of men to the armed forces. 



With its full staff, the division had been able to make normal 

 progress, although the task of putting the vast exhibits (Ernest R. 

 Graham Hall — Hall 38) in order, reinstalling a number of them, 

 and planning and installing others, had brought about some reduc- 

 tion in research. Curator Patterson made good progress in his 

 studies on the relationships of certain South American mammals 

 and birds. Dr. Albert A. Dahlberg, Research Associate, continued 

 his detailed studies on human dentition. 



Studies on fossil turtles were continued by Mr. Karl P. Schmidt, 

 Chief Curator of Zoology, and two papers describing new species 

 and new genera of Cretaceous and Paleocene forms were completed. 

 The Museum now has the types of three Cretaceous turtles from 

 Arkansas, the first to be described from the Mississippi Embayment, 

 and interesting for comparison with the numerous fossil turtles of 

 the Kansas Chalk. 



Dr. Paul 0. McGrew, Assistant Curator of Paleontology, com- 

 pleted his study of a Pleistocene fauna from north central Nebraska. 

 Although this fauna, mentioned in the Report for 1942, was small, 

 the conclusions derived from it are of considerable interest. The 

 glaciated regions of North America have never produced a mam- 

 malian fauna that could definitely be tied in to the earliest part of 

 the glacial period. Because of this, it has never been possible to 

 correlate certain important faunas from the western and southern 

 parts of the United States with faunas in the all-important glacial 

 sequence. The Nebraska fossils, fortunately, were found in a series 

 of deposits that appeared to be directly affected by the advance and 

 retreat of the major ice sheets of the Pleistocene. This geological 

 evidence, plus evidence derived from a rather large invertebrate 

 fauna, seems definitely to link this deposit and its mammalian fauna 

 with the earliest inter-glacial deposits of the glaciated regions. Thus 

 we have for the first time concrete evidence as to the age of the 

 western and southern faunas. This has necessitated a rather impor- 

 tant change in the epoch allocation of a large group of mammal- 

 bearing deposits. All of those beds of so-called Blancan age, formerly 

 regarded as Pliocene, are now believed to be of Pleistocene age. 



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