The fossil turtles of the Uinta formation

Abstract

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 together in the Carnegie Museum through the activities of its various expeditions to Utah. By the kindness of Dr. William J. Holland, the Dh-ector 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 fieldparties conducted by Messrs. Earl Douglass and O. A. Peterson and as an incidental 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