This dataset contains the digitized treatments in Plazi based on the original journal article Ponstein, Jasper, Wallaard, Jonathan J. W., Rijke, Maarten de, Fraaije, René H. B. (2024): The first cranium of Axestemys infernalis (Testudines: Trionychidae) from the Lance Formation of Wyoming, USA; an updated description and phylogenetic analysis. Palaeontologia Electronica (a 31) 27 (2): 1-33, DOI: 10.26879/1361, URL: https://doi.org/10.26879/1361
ABSTRACT
We report the first trionychid turtle skull from the Lance Formation (Maastrichtian) of Wyoming, USA, a relatively complete cranium of Axestemys infernalis. Included is an osteological and preliminary neuroanatomical description aided by a medical CTscan of the specimen. Comparison with other published crania of A. infernalis yielded considerable intraspecific variation. Notably, our specimen does not bear an ossified premaxilla, the postorbital extends ventrally and the maxilla-jugal suture is positioned posterior to the orbit. Based on this new anatomical data, both a parsimony and a Bayesian analysis of an updated character-taxon matrix of Trionychia have been run, which found A. infernalis as either outside Plastomenidae +Cyclanorbinae or as an early diverging stem-cyclanorbine. Moreover, for the first time a fossil trionychid braincase is described in detail.
Jasper Ponstein. AG Paläobiologie und Evolution, Institut für Biologie, Humboldt Universität zu Berlin, Unter den Linden 6, 10117 Berlin, Germany and Museum für Naturkunde Berlin, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstrasse 43, 10115 Berlin, Germany and Oertijdmuseum, Bosscheweg 80, 5283 WB Boxtel, Netherlands. Corresponding author. ponsteij@hu-berlin.de
Jonathan J.W. Wallaard. Oertijdmuseum, Bosscheweg 80, 5283 WB Boxtel, Netherlands.
curator@oertijdmuseum.nl
Maarten de Rijke. Oertijdmuseum, Bosscheweg 80, 5283 WB Boxtel, Netherlands.
maarten@oertijdmuseum.nl
René H.B. Fraaije. Oertijdmuseum, Bosscheweg 80, 5283 WB Boxtel, Netherlands.
info@oertijdmuseum.nl
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