Iguanian lizards from the Split Rock Formation, Wyoming: exploring the modernization of the North American lizard fauna

Late Pleistocene Herpetofauna from Two High-Elevation Caves in the Upper Gunnison Basin, Colorado

“…With the above characters and features discussed here and in Scarpetta (2021), the dentaries and maxillae are not members of the Crotaphytidae. The anterior teeth are not the distinctly delicate, highly pointed teeth typical of Urosaurus and Uta.…”

“…The alveolar surface curves dorsally, which gives the posterior portion of the dentary an exaggerated, greater height than the anterior portion. A dentary dorsal curvature is also observed in the other sceloporines ( Urosaurus and Uta ) and in the sand lizards, but typically is not as exaggerated, albeit there is much variation (see also Scarpetta 2021). All dentaries in this grouping lack the derived morphology observed in Phrynosoma (Mead et al 1999, Bell et al 2004a).…”

“…DISCUSSION.-Fossil specimens described here and within Sceloporus sp. small form (below) can be placed within the Phrynosomatidae based on the following dental and tooth-bearing bone characters: (1) constriction of the Meckelian groove, (2) closure of the Meckelian groove without fusion of the infra-and suprameckelian lips, and (3) gracile, minute (yet distinct) tricuspate teeth with unflared tooth crowns (see details in Etheridge and de Queiroz 1988, Bhullar and Smith 2008, Scarpetta 2021). Specimen 2010.14.5GN189.423 (representing all dentaries here) is a complete right dentary (length of 7.2 mm) with a tooth row of 12 teeth and space for additional 5 teeth.…”

“…This latter subclade is divided into 2 groups: (a) Phrynosoma and (b) Callisaurus , Cophosaurus , Holbrookia , and Uma . All lizard fossils described here are members of Lepidosauria based on the presence of pleurodont tooth implantation (Gauthier et al 1988, Scarpetta 2021).…”

A Palaeogene stem crotaphytid ( Aciprion formosum ) and the phylogenetic affinities of early fossil pleurodontan iguanians

“…I did not include isolated and fragmentary fossils, e.g. the fossil Uma from Scarpetta [60], the fossil phrynosomatine from Scarpetta [12], the fossil Pristidactylus from Albino et al [61], fossil Liolaemus from Albino [62], and the acrodontans Jeddaherdan from Apesteguía et al [63] and Gueragama from Simões et al [64]. Analysis of the last two taxa is more appropriate for a matrix with more Acrodonta-specific characters (e.g.…”