1Department of Anthropology, Binghamton University (SUNY), 2Division of Anthropology, American Museum of Natural History, 3Área de Evolución Humana, Centro UCM-ISCIII de Investigación sobre la Evolución y Comportamiento Humanos, 4Departamento de Paleontología, Universidad Complutense de Madrid
Friday Afternoon, 200DE
A placement of the mandibular mental foramen under the M1 occurs frequently in European Middle and Late Pleistocene Neandertal lineage specimens. These hominins are often described as showing a “more posterior” placement of the mental foramen, and this feature is often cited as a derived condition in Neandertals. The present study examines the position of the mental foramen in relation to the osteological marker gonion within the mandibular corpus in a taxonomically diverse sample of mandibles within the genus Homo. A very strong correlation (r = .991) was found between the distance of the mental foramen to gonion and the gonial length of the mandible. An index relying on these two variables shows remarkable stability across the genus Homo, suggesting little movement of the mental foramen within the mandibular corpus. The Neandertal lineage specimens show a mental foramen that is located only 3.3% (approximately 3.0 mm) more posteriorly, relative to gonial length, than in a pooled H. sapiens sample. However, this difference is insufficient to explain the change from a modal placement of the mental foramen under the P4 to the M1. Rather, than a posterior migration of the mental foramen within the body of the mandible, changes in the relationship of the dental arcade to the mandibular corpus seem to be a more likely explanation for the placement below the M1 in the Neandertal lineage sample. While this feature may still hold some descriptive value, the implications of the results for the identification of Neandertal derived traits is discussed.