On the relationship between maxillary molar root shape and jaw kinematics in Australopithecus africanus and Paranthropus robustus. Issue 8 (29th August 2018)

• Record Type: Journal Article
• Authors: Kupczik, Kornelius; Toro-Ibacache, Viviana; Macho, Gabriele A.
• Is Part Of: Royal Society open science. Volume 5:Issue 8(2018)
• Publication Date: 2018-08-29
• Subjects: Plio-Pleistocene hominins -- Australopithecus africanus -- Paranthropus robustus -- Paranthropus boisei -- tooth root splay -- dietary ecology; Science -- Periodicals; 500
• DOI: 10.1098/rsos.180825
• Languages: English
• ISSNs: 2054-5703

Abstract

Abstract : Plio-Pleistocene hominins from South Africa remain poorly understood. Here, we focus on how Australopithecus africanus and Paranthropus robustus exploited and—in part—partitioned their environment. Specifically, we explore the extent to which first maxillary molar roots (M 1 ) are oriented and thus, by proxy, estimate the direction of loads habitually exerted on the chewing surface. Landmark-based shape analysis of M 1 root reconstructions of 26 South African hominins and three East African Paranthropus boisei suggest that A. africanus may have been able to dissipate the widest range of laterally directed loads. Paranthropus robustus and P. boisei, despite having overlapping morphologies, differ in aspects of root shape/size, dento-cranial morphologies, microwear textures and C4 food consumption. Hence, while Paranthropus monophyly cannot be excluded, equivalence of dietary niche can. The South African hominins occupied distinct ecological niches, whereby P. robustus appears uniquely adapted to dissipate antero-posteriorly directed loads.