Ontogeny and taxonomy of Paurodon valens (Mammalia, Cladotheria) from the Upper Jurassic Morrison Formation of USA

A.O. Averianov and T. Martin

Proceedings of the Zoological Institute RAS, 2015, 319(3): 326–340 · https://doi.org/10.31610/trudyzin/2015.319.3.326

Full text

Abstract

Several basal cladotherian taxa previously referred to the “Paurodontidae” (Dryolestida) from the Upper Jurassic Morrison Formation of Wyoming, U.S.A. represent ontogenetic and individual variation of one single taxon, Paurodon valens Marsh, 1887 (= Archaeotrigon brevimaxillus Simpson, 1927, syn. n.; = Pelicopsis dubius Simpson, 1927, syn. n.; = Archaeotrigon distagmus Simpson, 1929, syn. n.; = Araeodon intermissus Simpson, 1937, syn. n.; = Foxraptor atrox Bakker et Carpenter, 1990, syn. n.). P. valens is characterized by prolonged dental replacement, including late eruption of m4 (and m5 as individual variation) and a time gap between shedding of dp2 and eruption of p2, which can be lost in aged individuals. By a shortened dentary and mandibular symphysis, two-three simple premolariform teeth, and four molariform teeth with tall trigonid and small talonid, P. valens is strinkingly similar to the modern golden moles (Chrysochloridae), particularly to Amblysomus hottentotus. This similarity suggests that P. valens was specialized on consuming earth worms in contrast to a more insectivorous diet characteristic for other dryolestidans.

Key words

Cladotheria, Dryolestida, Jurassic, Mammalia, Morrison Formation, ontogeny, Paurodon, taxonomy

Submitted June 8, 2015 · Accepted August 31, 2015 · Published September 25, 2015

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