Title

The Ardipithecus Ramidus Skull and Its Implications for Hominid Origins

Publication Title

Science

Publication Date

10-2-2009

Document Type

Article

DOI

10.1126/science.1175825

Keywords

ardipithecus ramidus skull, hominid origins

Disciplines

Anthropology

Abstract

The highly fragmented and distorted skull of the adult skeletonARA-VP-6/500 includes most of the dentition and preserves substantial parts of the face, vault, and base. Anatomical comparisons and micro–computed tomography–based analysis of this and other remains reveal pre-Australopithecus hominid craniofacial morphology and structure. The Ardipithecus ramidusskull exhibits a small endocranial capacity (300 to 350 cubic centimeters), small cranial size relative to body size, considerable midfacial projection, and a lack of modern African ape–like extreme lower facial prognathism. Its short posterior cranial base differs from that of both Pan troglodytes and P. paniscus. Ar. ramidus lacks the broad, anteriorly situated zygomaxillary facial skeleton developed in later Australopithecus. This combination of features is apparently shared bySahelanthropus, showing that the Mio-Pliocene hominid cranium differed substantially from those of both extant apes andAustralopithecus.