E-catalog        

Библиогр.: с. 41-51

This is the third and last of a series of reports that provide detailed descriptionsand taxonomic revisions of the fauna from the Turtle Bluff Member (TBM) of the middleEocene Bridger Formation of southwestern Wyoming. The TBM has been designatedas the stratotype section for biochron Ui1a (earliest Uintan) of the Uintan North Ameri-can Land Mammal age and here we document new faunal elements along with new U-Pb geochronologic and paleomagnetic data for the TBM. Prior to these reports,detailed systematic accounts of the taxa from the TBM were unavailable with theexception of one primate (Hemiacodon engardae). Here we document the occurrenceof the following didelphimorphian marsupials from the TBM: Herpetotherium knighti,Herpetotherium marsupium, Peradectes chesteri, and Peradectes californicus. New U-Pb dates of 47.31 ± 0.06 Ma and 46.94 ± 0.14 Ma from the TBM provide precise con-straints on the age of the fauna. These dates plus new paleomagnetic data further sup-port the existing evidence that the TBM Fauna and the boundary between theBridgerian and Uintan North American Land Mammal ages occurs within the lower partof Chron C21n of the Geomagnetic Polarity Time Scale. The only other fauna fromNorth America that can confidently be assigned to biochron Ui1a is the Basal TertiaryLocal Fauna from the Devil's Graveyard Formation of Texas. Revisions of the faunalcharacterizations of biochrons Ui1a (earliest Uintan) and Ui1b (early Uintan) of the Uin-tan North America Land Mammal age are proposed to further clarify their differences