A New Species of The Enigmatic Archosauromorph Doswellia from the Upper Triassic Bluewater Creek Formation, New Mexico, USA

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Andrew B. Heckert Ph.D., Professor (Creator)
Institution
Appalachian State University (ASU )
Web Site: https://library.appstate.edu/

Abstract: Doswellia sixmilensis is a new species of the dos-welliid archosauromorph genus Doswellia named for an incomplete skeleton from the Upper Triassic Bluewater Creek Formation of the Chinle Group in west-central New Mexico, USA. D. sixmilensis differs from D. kaltenbachi Weems, the type and only other known species of Doswellia, in its larger size, higher tooth count and greater heterodonty, possession of keels on the cervical centra and the presence of discrete knobs or spikes on some osteoderms. The holotype of D. six-milensis is the fourth occurrence of Doswellia and only the second occurrence of a Doswellia skull, which includes the previously unknown premaxilla and maxilla (and therefore the best dentition) and has the best-preserved cervical vertebrae. Although it adds to our knowledge of the anatomy of Doswellia, this new information does not alter previous concepts of the phylogenetic relationships of the doswelliid gen-era, largely because they are so poorly known anatomically. The genus Doswellia is known from the Newark Supergroup in Virginia, and the Chinle Group in Texas, New Mexico and Utah, in strata of Otischalkian–Adamanian age. The type locality of D. sixmilensis is c. 43 m stratigraphically below a bed from which U-Pb dating of detrital zircons yields a maximum depositional age of c. 220 Ma, so this is a reasonable approximate numerical age for D. sixmilensis.

Additional Information

Publication
Andrew B. Heckert, Spencer G. Lucas, & Justin A. Spielmann (2012) "A New Species of The Enigmatic Archosauromorph Doswellia from the Upper Triassic Bluewater Creek Formation, New Mexico, USA" Palaeontology Volume 55 Part 6 pp. 1333-1348 Version of Record Available from (www.citeseerx.ist.psu.edu)
Language: English
Date: 2012
Keywords
Upper Triassic, New Mexico, Archosauromor-pha, Doswelliidae, Chinle Group, Bluewater Creek Formation

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