A partial oviraptorosaur skeleton suggests low caenagnathid diversity in the Late Cretaceous Nemegt Formation of Mongolia

PLoS One. 2021 Jul 12;16(7):e0254564. doi: 10.1371/journal.pone.0254564. eCollection 2021.

Abstract

The Nemegt Formation of the Gobi Desert of Mongolia has produced one of the most abundant and diverse oviraptorosaur records globally. However, the caenagnathid component of this fauna remains poorly known. Two caenagnathid taxa are currently recognized from the Nemegt Formation: Elmisaurus rarus and Nomingia gobiensis. Because these taxa are known from mostly non-overlapping material, there are concerns that they could represent the same animal. A partial, weathered caenagnathid skeleton discovered adjacent to the holotype quarry of Nomingia gobiensis is referable to Elmisaurus rarus, revealing more of the morphology of the cranium, mandible, pectoral girdle, and pubis. Despite metatarsals clearly exhibiting autapomorphies of Elmisaurus rarus, overlapping elements are identical to those of Nomingia gobiensis, and add to a growing body of evidence that these taxa represent a single morphotype. In the absence of any positive evidence for two caenagnathid taxa in the Nemegt Formation, Nomingia gobiensis is best regarded as a junior synonym of Elmisaurus rarus. Low caenagnathid diversity in the Nemegt Formation may reflect broader coexistence patterns with other oviraptorosaur families, particularly oviraptorids. In contrast to North America, competition with the exceptionally diverse oviraptorids may have restricted caenagnathids to marginal roles in Late Cretaceous Asian ecosystems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dinosaurs / anatomy & histology*
  • Dinosaurs / classification*
  • Ecosystem
  • Fossils
  • Mandible / anatomy & histology
  • Mongolia
  • Paleontology / methods*
  • Phylogeny
  • Skull / anatomy & histology

Grants and funding

Funding to GFF for travel and research in Mongolia was provided by a Michael Smith Foreign Study Supplement from NSERC (https://www.nserc-crsng.gc.ca/index_eng.asp) and Vanier Canada (https://vanier.gc.ca). GFF is funded by the Royal Society [Grant NIF\R1\191527] (https://royalsociety.org/). PJC is funded by the Natural Sciences and Engineering Research Council of Canada [Grant RGPIN-2017-04715] (https://www.nserc-crsng.gc.ca/index_eng.asp). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.