Skip to content Skip to navigation

Article: Dietary shifts in a group of early Eocene euarchontans (Microsyopidae) in association with climatic change

Palaeontology - Vol. 64 - Cover Image
Publication: Palaeontology
Volume: 64
Part: 5
Publication Date: September 2021
Page(s): 609 628
Author(s): Keegan R. Selig, Amy E. Chew, and Mary T. Silcox
Addition Information

How to Cite

SELIG, K.R., CHEW, A.E., SILCOX, M.T. 2021. . Palaeontology, 64, 5, 609-628. DOI: /doi/10.1111/pala.12544

Author Information

  • Keegan R. Selig - Department of Anthropology University of Toronto Scarborough Toronto ON Canada
  • Amy E. Chew - Department of Ecology and Evolutionary Biology Brown University Providence RI USA
  • Mary T. Silcox - Department of Anthropology University of Toronto Scarborough Toronto ON Canada

Publication History

    Online Version Hosted By

    Wiley Online Library
    Get Article: Wiley Online Library [Pay-to-View Access] |


    Microsyopidae is a family of plesiadapiforms known from over 1500 stratigraphically controlled specimens from the southern Bighorn Basin of Wyoming spanning the first three million years of the early Eocene. The early Eocene is characterized by rapid fluctuations in climate during the period represented by this collection of microsyopids, making this an ideal sample to examine how climate may have influenced early stem primate biology, particularly diet. An evolving lineage of microsyopids is known from before, during, and after Biohorizon A, a faunal turnover event associated with a period of localized cooling. Dental topographic analysis (DTA) metrics quantify functional aspects of molars including curvature, complexity and relief, and covary with diet in extant taxa. Here, we use DTA to examine microsyopid dietary change over time, particularly in association with this cooling event. Our results suggest that microsyopids had molars that are functionally like extant insectivorous/omnivorous euarchontans. The earliest occurring species, Arctodontomys wilsoni, is characterized by molars that became more like modern insectivores over time. During Biohorizon A, Awilsoni is replaced by Anuptus, which has molars that are more like those of extant omnivores with a mixed diet including fruit. After Biohorizon A, Anuptus appears more insectivorous, as is the later occurring Microsyops angustidens, which evolves from Anuptus. Overall, we provide potential evidence for a causal scenario in which local climate change coincided with a dietary transition among microsyopids. Our results have implications for understanding how diet was a prime mover for the evolution of Primates.

    PalAss Go! URL: | Twitter: Share on Twitter | Facebook: Share on Facebook | Google+: Share on Google+