A new stegosaur from the late Early Cretaceous of Zuoyun, Shanxi Province, China

ABSTRACT

Stegosaurs are a minor but iconic clade of ornithischian dinosaurs. They range from the Middle Jurassic to the Early Cretaceous, but are rare and poorly represented in the Cretaceous. Before this study, there were only four valid taxa from the Cretaceous: Paranthodon, Wuerhosaurus homheni, Wuerhosaurus ordosensis and Mongolostegus exspectabilis. Here, we describe a new stegosaur, Yanbeilong ultimus gen. et sp. nov. from the late Early Cretaceous Zuoyun Formation (Albian in age) of Zuoyun County, Shanxi Province, P. R. China. Yanbeilong represents one of the latest records of a stegosaurian taxon in the world. Compared to other stegosaurs, Yanbeilong has several unique characteristics in dorsal vertebrae and ilio-sacral block: it has a higher neural arch and smaller neural canal of dorsal vertebrae, and it has fewer number of fused vertebrae/sacrals and fenestrae/sacral ribs in the ilio-sacral block. Although phylogenetic analysis shows that Yanbeilong is recovered as the sister taxon to a clade containing Stegosaurus stenops and Wuerhosaurus homheni, it differs from these two taxa in several anatomical characters of dorsasacral vertebrae ribs, sacral ribs, caudal vertebrae and ilium.

KEYWORDS:

• Dinosaur
• stegosaur
• Late Early Cretaceous
• Zuoyun
• Shanxi

Acknowledgments

We are grateful to field staff and preparators of Shanxi Museum of Geology for their dedicative work of discovering, excavating, and preparing the specimen; to Mr. Tang Zhilu for his help in early stages of the work; to Mr. Wang Runfu, the former director of Shanxi Museum of Geology, who led the ‘Vertebrate Fossil Survey in Key Areas of Shanxi’ project.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/08912963.2024.2308214

Additional information

Funding

This research was supported by the National Natural Science Foundation of China Grant No. [42288201], [42372030]. The fossil materials of this study results from the ‘Vertebrate Fossil Survey in Key Areas of Shanxi’ project supported by the Department of Finance of Shanxi.