A new early-branching armoured dinosaur from the Lower Jurassic of southwestern China

  1. Xi Yao
  2. Paul M Barrett
  3. Lei Yang
  4. Xing Xu  Is a corresponding author
  5. Shundong Bi  Is a corresponding author
  1. Yunnan University, China
  2. Natural History Museum, United Kingdom
  3. Yimen Administration of Cultural Heritage, China
  4. Chinese Academy of Sciences, China
  5. Indiana University of Pennsylvania, United States

Abstract

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.

Data availability

All data generated or analysed during this study are included in the manuscript and Supplementary Information.

Article and author information

Author details

  1. Xi Yao

    Centre for Vertebrate Evolutionary Biology, Yunnan University, Kunming, China
    Competing interests
    The authors declare that no competing interests exist.
  2. Paul M Barrett

    Department of Earth Sciences, Natural History Museum, London, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0412-3000
  3. Lei Yang

    Yimen Administration of Cultural Heritage, Yimen, China
    Competing interests
    The authors declare that no competing interests exist.
  4. Xing Xu

    Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
    For correspondence
    xu.xing@ivpp.ac.cn
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4786-9948
  5. Shundong Bi

    Department of Biology, Indiana University of Pennsylvania, Indiana, United States
    For correspondence
    sbi@iup.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0620-187X

Funding

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.

Reviewing Editor

  1. George H Perry, Pennsylvania State University, United States

Version history

  1. Received: November 3, 2021
  2. Preprint posted: November 25, 2021 (view preprint)
  3. Accepted: February 2, 2022
  4. Accepted Manuscript published: March 15, 2022 (version 1)
  5. Version of Record published: March 17, 2022 (version 2)

Copyright

© 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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  1. Xi Yao
  2. Paul M Barrett
  3. Lei Yang
  4. Xing Xu
  5. Shundong Bi
(2022)
A new early-branching armoured dinosaur from the Lower Jurassic of southwestern China
eLife 11:e75248.
https://doi.org/10.7554/eLife.75248

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https://doi.org/10.7554/eLife.75248

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