Trilophosaurus (Archosauromorpha: Trilophosauridae) Postcrania From The Upper Triassic Blue Mesa Member Of The Petrified Forest Formation (Carnian: Adamanian), Arizona, Usa

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Andrew B. Heckert Ph.D., Professor (Creator)
Appalachian State University (ASU )
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Abstract: Trilophosaurus is a genus of Late Triassic archosauromorph known exclusively from the American Southwest. The defining characteristic of the taxon is its transversely arranged, tricuspid teeth. Here, we document various Trilophosaurus postcrania from the Krzyzanowski bonebed, NMMNH locality 3764, a multi-taxicbonebed located in the Blue Hills of Apache County, Arizona. These postcrania represent the first Trilophosaurus remains identified based solely on postcrania, in the absence of cranial or dental material. The Trilophosaurusspecimens collected from NMMNH locality 3764 consist of two cervical vertebrae, two dorsal vertebrae, an incomplete humerus, a right ulna, a nearly complete right radius, an articulated left ilium and ischium, an isolated left ilium, three femora, an incomplete left tibia and an isolated right astragalus. The most prominent diagnosticcharacter uniting the Krzyzanowski bonebed specimens and Trilophosaurus is the large, extensive internal trochanter on the femur and the overall morphology of the astragalus. We tentatively identify the Krzyzanowski specimens as pertaining to Trilophosaurus cf. T. jacobsi based on various shared features of the cervical vertebrae, humeri and ulnae. The presence of Trilophosaurus cf. T. jacobsi within the lowermost Blue Mesa Member of the Petrified Forest Formation is consistent with the established biostratigraphic range of T. jacobsi.

Additional Information

Spielmann, J.A., Lucas, S.G., Heckert, A.B., and Krzyzanowski, S.E. (2013) Trilophosaurus (Archosauromorpha: Trilophosauridai) Postcrania from the Upper Triassic Blue Mesa Member of the Petrified Forest Formation (Carnian: Adamanian), Arizona, USA. New Mexico Museum of Natural History and Science, Bulletin 61: 567-572 (ISSN: 1524-4156).
Language: English
Date: 2013

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