The foot of Homo naledi.

M S M Drapeau,B Zipfel,A S Deane,K A Congdon,J M Desilva,S E Churchill,L R Berger,W E H Harcourt-Smith,Z Throckmorton

doi:10.1038/ncomms9432

M S M Drapeau, B Zipfel + Show 7 more

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https://doi.org/10.1038/ncomms9432

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Abstract

Modern humans are characterized by a highly specialized foot that reflects our obligate bipedalism. Our understanding of hominin foot evolution is, although, hindered by a paucity of well-associated remains. Here we describe the foot of Homo naledi from Dinaledi Chamber, South Africa, using 107 pedal elements, including one nearly-complete adult foot. The H. naledi foot is predominantly modern human-like in morphology and inferred function, with an adducted hallux, an elongated tarsus, and derived ankle and calcaneocuboid joints. In combination, these features indicate a foot well adapted for striding bipedalism. However, the H. naledi foot differs from modern humans in having more curved proximal pedal phalanges, and features suggestive of a reduced medial longitudinal arch. Within the context of primitive features found elsewhere in the skeleton, these findings suggest a unique locomotor repertoire for H. naledi, thus providing further evidence of locomotor diversity within both the hominin clade and the genus Homo.

Highlights

The Homo sapiens foot is highly adapted to striding bipedalism, and possesses a suite of anatomical features that functionally relate to this form of locomotion[1,2]
In the last 20 years, our understanding of the evolution of human pedal function has become complicated by fossil discoveries that point to diversity in the types of terrestrial bipedalism found throughout the hominin clade, including several instances where contemporary hominin taxa possessed different combinations of pedal morphologies, indicating distinct differences in foot function[3,4,5,6]
Full descriptions of talus and calcaneus, as well as all other pedal elements currently assigned to H. naledi, are provided in Supplementary Note 1

Summary

Introduction

The Homo sapiens foot is highly adapted to striding bipedalism, and possesses a suite of anatomical features that functionally relate to this form of locomotion[1,2]. Neither the talar head nor the proximal navicular facet is extended dorsally, indicating a modern human-like range of dorsiflexion and rotation at the talonavicular joint, which is limited compared with that of chimpanzees[12,13].

Results

Conclusion