A new polyglyphanodontian lizard with a complete lower temporal bar from the Upper Cretaceous of southern China

Polyglyphanodontians were a dominant terrestrial lizard group during the Cretaceous. They were mainly distributed across Laurasia but show their greatest diversity in the Upper Cretaceous deposits of China and Mongolia. Several of the Asian taxa were comparatively large, with robust skulls and a dentition specialized for herbivory. Two polyglyphanodontian genera, Tianyusaurus from China and Polyglyphanodon from North America, are unusual in having developed a complete, or near complete, lower temporal bar. Here we describe a third polyglyphanodontian with a complete lower temporal bar, Yechilacerta yingliangia gen. et sp. nov., from the Upper Cretaceous of Jiangxi Province, southern China. These deposits have also yielded specimens of Tianyusaurus, but the new genus differs from Tianyusaurus in several key aspects of skull and dental morphology, including the presence of coarse pustulate cranial sculpture, and the absence of maxillary caniniform teeth. Phylogenetic analysis places the new genus and species as the sister taxon to Tianyusaurus, with both taxa nested among East Asian gilmoreteiids. Previous phylogenetic analyses using morphological characters have mostly placed polyglyphanodontians close to extant teiioid lizards, but our analyses, using a constraint tree for squamates based on published molecular phylogenies, placed Polyglyphanodontia closer to Iguania. However, a more comprehensive review is needed to resolve their relationships.http://zoobank.org/urn:lsid:zoobank.org:pub:53B9CE04-E600-48AE-AC98-7476A949BCBD