First occurrence of the enigmatic peccaries Mylohyus elmorei and Prosthennops serus from the Appalachians: latest Hemphillian to Early Blancan of Gray Fossil Site, Tennessee

Evan M Doughty; Steven C Wallace; Blaine W Schubert; Lauren M Lyon

doi:10.7717/peerj.5926

First occurrence of the enigmatic peccaries Mylohyus elmorei and Prosthennops serus from the Appalachians: latest Hemphillian to Early Blancan of Gray Fossil Site, Tennessee

PeerJ. 2018 Nov 30:6:e5926. doi: 10.7717/peerj.5926. eCollection 2018.

Authors

Evan M Doughty¹, Steven C Wallace², Blaine W Schubert², Lauren M Lyon^{2

3}

Affiliations

¹ Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, United States of America.
² Department of Geosciences and Don Sundquist Center of Excellence in Paleontology, East Tennessee State University, Johnson City, TN, United States of America.
³ Department of Ecology and Evolutionary Biology, University of Tennessee-Knoxville, Knoxville, TN, United States of America.

Abstract

Two peccary species, Mylohyus elmorei and Prosthennops serus are described from the medium-bodied fauna of the Gray Fossil Site (GFS) of northeastern Tennessee. This site, recognized as an oak-hickory forest, is latest Hemphillian or earliest Blancan based on mammalian biochronology, with an estimated age of 4.9-4.5 Ma. The GFS represents the only site outside the Palmetto Fauna of Florida with M. elmorei, greatly expanding the species range north over 920 km, well into the Appalachian region. This is also the first Appalachian occurrence of the relatively widespread P. serus. Our understanding of intraspecific variation for both M. elmorei and P. serus is expanded due to morphological and proportional differences found in cranial and dental material from the GFS, Tyner Farm locality, Palmetto Fauna, and within the literature. The GFS M. elmorei material represents the most complete mandible and second cranium for the species, and preserve intraspecific variation in the length of the diastema, dental proportions, and the complexity of the cuspules of the hypoconulid complex. Similarly, mandibular material from the GFS for P. serus exhibited larger dentitions and a greater degree of robustness than currently recognized for the species.

Keywords: Artiodactyla; Early blancan; Gray Fossil Site; Hypoconule/hypoconulid complex; Intraspecific variation; Latest Hemphillian; Niche partitioning; Paleontology; Tayassudiae; Tayassuinae.

Grants and funding

This research was supported by the National Science Foundation (EAR-0958985), and the following divisions of ETSU: Don Sundquist Center of Excellence in Paleontology, Research and Sponsored Programs, and the Department of Geosciences. University of Florida specimens were photographed under NSF grant CSBR 1203222. There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.