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

Abstract

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

Keywords:

• Squamata
• Polyglyphanodontia
• China
• Cretaceous
• skull

Acknowledgements

The authors thank Kaifeng Wu (Yingliang Stone Nature History Museum) for preparation of the specimens, Qinfang Fang (China University of Geosciences, Beijing) for the preliminary CT scans, and Donghao Wang (doctoral student, China University of Geosciences) for making the map in Figure 1 and helping to collate geological background data. Funding for Lida Xing came from the National Natural Science Foundation of China (No. 41888101, 41790455), the 111 project (B20011), and the Fundamental Research Funds for Central Universities (265QZ201903). We also acknowledge the Willi Hennig Society for free access to the TNT phylogenetic program. We thank the editor and three reviewers for their contributions to the revised version of the manuscript.

Disclosure statement

The authors report that there are no competing interests to declare.

Supplemental material

Supplemental material for this article can be accessed here: https://doi.org/10.1080/14772019.2023.2281494.

Associate Editor: Jennifer Olori

Additional information

Funding

Higher Education Discipline Innovation Project;Fundamental Research Funds for Central Universities, China.