A new early-branching armoured dinosaur from the Lower Jurassic of southwestern China
The early evolutionary history of the armoured dinosaurs (Thyreophora) is obscured by their patchily distributed fossil record and by conflicting views on the relationships of Early Jurassic taxa. Here, we describe an early-diverging thyreophoran from the Lower Jurassic Fengjiahe Formation of Yunnan Province, China, on the basis of an associated partial skeleton that includes skull, axial, limb and armour elements. It can be diagnosed as a new taxon based on numerous cranial and postcranial autapomorphies and is further distinguished from all other thyreophorans by a unique combination of character states. Although the robust postcranium is similar to that of more deeply nested ankylosaurs and stegosaurs, phylogenetic analysis recovers it as either the sister taxon of Emausaurus or of the clade Scelidosaurus+Eurypoda. This new taxon, Yuxisaurus kopchicki, represents the first valid thyreophoran dinosaur to be described from the Early Jurassic of Asia and confirms the rapid geographic spread and diversification of the clade after its first appearance in the Hettangian. Its heavy build and distinctive armour also hint at previously unrealised morphological diversity early in the clade's history.
All data generated or analysed during this study are included in the manuscript and Supplementary Information.
Article and author information
Double First-Class joint program of Yunnan Science & Technology and Yunnan University (2018FY001-005)
- Shundong Bi
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- George H Perry, Pennsylvania State University, United States
- Received: November 3, 2021
- Preprint posted: November 25, 2021 (view preprint)
- Accepted: February 2, 2022
- Accepted Manuscript published: March 15, 2022 (version 1)
- Version of Record published: March 17, 2022 (version 2)
© 2022, Yao et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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