A New Specimen of Carroll's Mystery Hupehsuchian from the Lower Triassic of China

PLoS One. 2015 May 27;10(5):e0126024. doi: 10.1371/journal.pone.0126024. eCollection 2015.

Abstract

A new specimen of an enigmatic hupehsuchian genus is reported. The genus was first recognized by Robert L. Carroll and Zhi-ming Dong in 1991, who refrained from naming it because of the poor quality of the only specimen known at the time. After more than two decades, we finally report a second specimen of this genus, which remained unprepared until recently. The new specimen preserves most of the skeleton except the skull, allowing us to erect a new genus and species, Eretmorhipis carrolldongi. The new species shares many characters with Parahupehsuchus longus, including the strange axial skeleton that forms a bony body tube. However, the body tube is short in the new species, being limited to the pectoral region. The vertebral count and limb morphology considerably differ between the new species and P. longus. The forelimb of E. carrolldongi is markedly larger than its hind limb as in Hupehsuchus nanchangensis but unlike in P. longus. The new species is unique among hupehsuchians in a list of features. It has manual and pedal digits that spread radially, forming manus and pes that are almost as wide as long. The third-layer elements of the dermal armor are unusually large, spanning four vertebral segments, yet there are substantial gaps among them. With the addition of the unique paddle, it is now clear that Hupehsuchia had diverse forelimb morphologies spanning from paddles to flippers, unlike ichthyopterygians that were taxonomically more diverse yet only had flippers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • China
  • Forelimb / anatomy & histology
  • Fossils / anatomy & histology*
  • Hindlimb / anatomy & histology
  • Phylogeny
  • Reptiles / anatomy & histology*
  • Ribs / anatomy & histology
  • Spine / anatomy & histology

Grants and funding

Funding provided by Ministry of Land and Resources, China (http://www.mlr.gov.cn/mlrenglish/), Special project for scientific research Project 201311062 to Xiao-hong Chen, China Geological Survey (http://en.cgs.gov.cn/),Project 1212011120148 to Long Cheng, National Natural Science Foundation of China (http://www.nsfc.gov.cn/publish/portal1/), Projects 40920124002 and 41372016 to Da-yong Jiang and Ministry of Education, China (http://en.ustc.edu.cn/dictionary/201105/t20110509_111375.html), Research Fund for the Doctoral Program of Higher Education Project 20120001110072 to Da-yong Jiang. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.