)*N 23 1917 



MEMOIRS 



OF THE 



CAENEGIE MUSEUM. 



VOL. VII. NO. 2. 



THE FOSSIL TURTLES OF THE UINTA FORMATION. 



By Charles W. Gilmore. 



The finest and most complete assemblage of the remains of fossil turtles as 

 yet secured from the Upper Eocene of the Uinta formation has been brought to- 

 gether in the Carnegie Museum through the activities of its various expeditions 

 to Utah. By the kindness of Dr. William J. Holland, the Director of the Museum, 

 I have been permitted to study this collection, and the present paper presents the 

 results of my investigations. 



The collection comprises more than fifty individuals, and was made by field- 

 parties conducted by Messrs. Earl Douglass and 0. A. Peterson and as an in- 

 cidental part of their search of the Uinta exposures for the remains of extinct 

 mammals. An important feature of this collection is the determination of the 

 exact geological horizons in which the specimens were found, thus establishing 

 a firm foundation for future correlative work. 



The chelonian fauna of the Uinta formation is of peculiar interest, since it 

 marks the last appearance of several forms which had their beginning, so far as 

 our present records go, in the Upper Cretaceous and Lower Tertiary. Of the six 

 genera recognized in the present collection from the Uinta formation only three, 

 Anosteira, Amyda, and Testudo, are known to pass upward into the younger 

 Tertiaries. Anosteira is known from the Lower Oligocene of England, Amyda 

 reappears in the Miocene of the Atlantic coast, while Testudo is found in the 

 overlying Oligocene. It appears that the Uinta thus marks an important stage in 

 the history of the chelonian life of the Upper Eocene. 



The Baenidae make their last appearance. The Dermatemydidse are rep- 



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