Early hominin auditory ossicles from South Africa.

Bibliographic Collection: 
Publication Type: Journal Article
Authors: Quam, Rolf M; de Ruiter, Darryl J; Masali, Melchiorre; Arsuaga, Juan-Luis; Martínez, Ignacio; Moggi-Cecchi, Jacopo
Year of Publication: 2013
Journal: Proc Natl Acad Sci U S A
Volume: 110
Issue: 22
Pagination: 8847-51
Date Published: 2013 May 28
Publication Language: eng
ISSN: 1091-6490
Keywords: Anatomy, Comparative, Animals, Biological Evolution, Body Weights and Measures, Ear Ossicles, Fossils, Hominidae, South Africa, Species Specificity

The middle ear ossicles are only rarely preserved in fossil hominins. Here, we report the discovery of a complete ossicular chain (malleus, incus, and stapes) of Paranthropus robustus as well as additional ear ossicles from Australopithecus africanus. The malleus in both early hominin taxa is clearly human-like in the proportions of the manubrium and corpus, whereas the incus and stapes resemble African and Asian great apes more closely. A deep phylogenetic origin is proposed for the derived malleus morphology, and this may represent one of the earliest human-like features to appear in the fossil record. The anatomical differences found in the early hominin incus and stapes, along with other aspects of the outer, middle, and inner ear, are consistent with the suggestion of different auditory capacities in these early hominin taxa compared with modern humans.

DOI: 10.1073/pnas.1303375110
Alternate Journal: Proc. Natl. Acad. Sci. U.S.A.