Vertical support use and primate origins.

Loading...
Thumbnail Image

Date

2019-08

Authors

Yapuncich, Gabriel S
Feng, Henry J
Dunn, Rachel H
Seiffert, Erik R
Boyer, Doug M

Journal Title

Journal ISSN

Volume Title

Repository Usage Stats

12
views
5
downloads

Citation Stats

Abstract

Adaptive scenarios of crown primate origins remain contentious due to uncertain order of acquisition and functional significance of the clade's diagnostic traits. A feature of the talus bone in the ankle, known as the posterior trochlear shelf (PTS), is well-regarded as a derived crown primate trait, but its adaptive significance has been obscured by poorly understood function. Here we propose a novel biomechanical function for the PTS and model the talus as a cam mechanism. By surveying a large sample of primates and their closest relatives, we demonstrate that the PTS is most strongly developed in extant taxa that habitually grasp vertical supports with strongly dorsiflexed feet. Tali of the earliest fossils likely to represent crown primates exhibit more strongly developed PTS cam mechanisms than extant primates. As a cam, the PTS may increase grasping efficiency in dorsiflexed foot postures by increasing the path length of the flexor fibularis tendon, and thus improve the muscle's ability to maintain flexed digits without increasing energetic demands. Comparisons are made to other passive digital flexion mechanisms suggested to exist in other vertebrates. These results provide robust anatomical evidence that the habitual vertical support use exerted a strong selective pressure during crown primate origins.

Type

Journal article

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1038/s41598-019-48651-x

Publication Info

Yapuncich, Gabriel S, Henry J Feng, Rachel H Dunn, Erik R Seiffert and Doug M Boyer (2019). Vertical support use and primate origins. Scientific reports, 9(1). p. 12341. 10.1038/s41598-019-48651-x Retrieved from https://hdl.handle.net/10161/26040.

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.


Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.