Manus Descriptions of an Undescribed Mastodon from the Latest Miocene-Earliest Pliocene Gray Fossil Site, with Comparisons to other North American Proboscidean Taxa

Abstract

A detailed morphological description of a proboscidean manus from the Gray Fossil Site (GFS), Gray, Tennessee is provided. Manus elements from an American mastodon (Mammut americanum), a Britt’s shovel-tusker (Amebelodon britti), an undescribed small gomphothere species, and a Columbian mammoth (Mammuthus columbi) are used for comparisons. Linear measurements indicate proportional differences between the GFS mastodon and other proboscidean taxa ranging from the Hemphillian to Rancholabrean land mammal ages. Possible pathologies are also described. The purpose of this study is to determine how the GFS mastodon differs in manus morphology and locomotion from different proboscidean taxa, including size, environmental, evolutionary, and taxonomic factors. Morphological differences are more pronounced in carpals and metacarpals in regard to shape, size, and orientation of articular surfaces but are not statistically compared due to the small sample size