Variation in the Modified First Metatarsal of a Large Sample of <em>Tapirus polkensis</em> and the Functional Implications for Ceratomorphs.

<p>The Mio-Pliocene age Gray Fossil Site of northeastern Tennessee has the largest collection of tapir postcranial skeletons in the world. Though representing a single species, a few localized structures show high variability. This paper deals with variation of the first metatarsal, which in tapirs was reduced as an early adaptation for running and then retrofitted to serve as a special origin for flexors and adductors of the proximal phalanges. The first metatarsal connects the medial ankle with a posterior process of the third metatarsal in tapiroids. In <em>Tapirus indicus</em>, <em>T. webbi</em>, and 6 out of 31 <em>T. polkensis</em> feet at Gray, it extends more laterally to articulate with the fourth metatarsal. This condition is too variable for species distinction but is correlated with a decrease in the metatarsophalangeal joint facet, suggesting a mobility reduction likely related to the increased range and feeding strategy seen in extant <em>T. indicus</em>.</p>

Name thesis:degree_name

MS (Master of Science)

Level thesis:degree_level

Thesis - unrestricted

Discipline thesis:degree_discipline

Biology

Year dc:date.issued

2011

Author dc:creator

• Hawkins, Patrick Lawrence

• variation
• metatarsal
• Gray Fossil Site
• Tapirus
• Earth Sciences
• Paleontology
• Physical Sciences and Mathematics

Statement dc:rights

• Copyright by the authors.

Repository record dc:identifier

https://dc.etsu.edu/etd/1241

OAI identifier oai:identifier

oai:dc.etsu.edu:etd-2432