LATE CRETACEOUS MICROHERPETOFAUNAS OF THE KAIPAROWITS PLATEAU, UTAH

Robert D. McCord, Department of Ecology and Evolutionary Biology,
University of Arizona, Tucson, Arizona 85721 and
Mesa Southwest Museum, 53 North Macdonald Street,
Mesa, Arizona 85201
mcord@ccit.arizona.edu

At least 22 genera in 16 families of small reptiles and amphibians have been recovered from the Dakota, Straight Cliffs, Wahweap and Kaiparowits Formations on the Kaiparowits Plateau, ranging in age from Cenomanian through Campanian. These fossils are significant for three reasons: 1, microherpetofaunas are poorly known in southern Cretaceous localities of the West; 2, microherpetofaunas are poorly known from before the late Campanian (Judithian) of North America; and, 3, the Kaiparowits Plateau affords a picture of the changes in the microherpetofauna in one area from Turonian throughout Campanian. These faunas include widespread Mesozoic forms, typical southern forms such as the polyglyphanodontines, and unique forms such as a new genus of polyglyphanodontine lizard. The occurrence of polyglyphanodontine lizards in the Kaiparowits region reinforces the notion that they are a typical component of the western portion of the "southern community" during the late Cretaceous. The early occurrence (Turonian) of Paraglyphanodon here raises the possibility that the subfamily was widespread in the poorly documented early Late Cretaceous, accounting for the subfamily’s Asian-Western North American distribution.

References:

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