An unusual archosauriform tooth increases known tetrapod diversity in the lower Chinle Formation (Late Triassic) of southeastern Utah
- Published
- Accepted
- Subject Areas
- Biodiversity, Paleontology
- Keywords
- archosaur, archosauriform, Chinle Formation, Triassic, tetrapod, dental taxon, Utah, Crosbysaurus, Revueltosaurus, phytosaur
- Copyright
- © 2015 Lopez et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2015. An unusual archosauriform tooth increases known tetrapod diversity in the lower Chinle Formation (Late Triassic) of southeastern Utah. PeerJ PrePrints 3:e1110v2 https://doi.org/10.7287/peerj.preprints.1110v2
Abstract
An unusual tetrapod tooth was discovered in the Late Triassic Chinle Formation of southeastern Utah. The tooth was originally thought to belong to Revueltosaurus but further investigations have rejected that hypothesis. In this paper we compare MNA V10668 to other known fossil teeth found in the Chinle Formation and identify the least inclusive clade it may belongs to. Using data found in other publications and pictures of other teeth, we compare this specimen to other Triassic dental taxa. MNA V10668 shares some similarities with Crosbysaurus, Tecovasaurus, and several other named taxa but possesses unique characteristics not found in other diapsid teeth. We conclude that it is most likely an archosauromorph and probably an archosauriform. This increases the known diversity of tetrapods from the Chinle Formation and represents the first tooth morphotype completely unique to Utah in the Late Triassic Period.
Author Comment
Updates to photos, description, and diagnosis. This version will be the initial version submitted for peer review.
Supplemental Information
Figure 1: The location of Comb Ridge in the state of Utah. Modified from Gay and St. Aude (2015)
The location of Comb Ridge (star) within the state of Utah. San Juan County is highlighted. Modified from Gay and St. Aude (2015).
Figure 2: Tetrapod tooth in situ at The Hills Have Teeth (MNA locality 1724), showing the lithology of the fossil-bearing layer
Small, unidentified tetrapod in the field in May 2015 showing the lithology of the fossil-bearing layer at The Hills Have Teeth. Site is dominated by gray-white mudstone with carbonaceous clasts.
Figure 3: Photographs of MNA V10668
MNA V10668 in A) lingual, B) labial, C) distal, D) mesial, E) apical, and F) basal views. Scale bar = 1 mm.
Figure 4: Interpretive line drawing of MNA V10668
Interpretive line drawing of MNA V10668 in A) lingual, B) labial, C) distal, D) mesial, E) apical, and F) basal views. In A-D, dark gray represents missing enamel, light gray represents a resorption pit. In E and F no missing enamel is figured; dark gray represents worn apex, light gray represents resorption pit. Scale bar = 1 mm.
Figure 5: Juvenile phytosaur jaws
Juvenile phytosaur jaws. Top: PEFO 13890/MNA V1789, Macheroprosopus zunii premaxillae in A) ventral view. Bottom: MNA V3601 right dentary in B) lateral C) dorsal views. Scale bar = 1 cm.
