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.

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.

Metrics

  • 3,489
    views
  • 546
    downloads
  • 13
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  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

Share this article

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

Further reading

    1. Ecology
    Luis Abdala-Roberts, Adriana Puentes ... Kailen A Mooney
    Review Article

    Global change is causing unprecedented degradation of the Earth’s biological systems and thus undermining human prosperity. Past practices have focused either on monitoring biodiversity decline or mitigating ecosystem services degradation. Missing, but critically needed, are management approaches that monitor and restore species interaction networks, thus bridging existing practices. Our overall aim here is to lay the foundations of a framework for developing network management, defined here as the study, monitoring, and management of species interaction networks. We review theory and empirical evidence demonstrating the importance of species interaction networks for the provisioning of ecosystem services, how human impacts on those networks lead to network rewiring that underlies ecosystem service degradation, and then turn to case studies showing how network management has effectively mitigated such effects or aided in network restoration. We also examine how emerging technologies for data acquisition and analysis are providing new opportunities for monitoring species interactions and discuss the opportunities and challenges of developing effective network management. In summary, we propose that network management provides key mechanistic knowledge on ecosystem degradation that links species- to ecosystem-level responses to global change, and that emerging technological tools offer the opportunity to accelerate its widespread adoption.

    1. Ecology
    2. Evolutionary Biology
    Vendula Bohlen Šlechtová, Tomáš Dvořák ... Joerg Bohlen
    Research Article

    Eurasia has undergone substantial tectonic, geological, and climatic changes throughout the Cenozoic, primarily associated with tectonic plate collisions and a global cooling trend. The evolution of present-day biodiversity unfolded in this dynamic environment, characterised by intricate interactions of abiotic factors. However, comprehensive, large-scale reconstructions illustrating the extent of these influences are lacking. We reconstructed the evolutionary history of the freshwater fish family Nemacheilidae across Eurasia and spanning most of the Cenozoic on the base of 471 specimens representing 279 species and 37 genera plus outgroup samples. Molecular phylogeny using six genes uncovered six major clades within the family, along with numerous unresolved taxonomic issues. Dating of cladogenetic events and ancestral range estimation traced the origin of Nemacheilidae to Indochina around 48 mya. Subsequently, one branch of Nemacheilidae colonised eastern, central, and northern Asia, as well as Europe, while another branch expanded into the Burmese region, the Indian subcontinent, the Near East, and northeast Africa. These expansions were facilitated by tectonic connections, favourable climatic conditions, and orogenic processes. Conversely, aridification emerged as the primary cause of extinction events. Our study marks the first comprehensive reconstruction of the evolution of Eurasian freshwater biodiversity on a continental scale and across deep geological time.