2 Defining Hominidae

Abstract

I review the relevant skeletal evidence that would unite a group that includes extant humans and their fossil relatives to the exclusion of living hominoids. Practicality suggests this group be called Hominidae. Potential hominid postcranial synapomorphies include a distinct angle at L5-S1, a long pubic ramus, a superoinferiorly short ilium that is roundedly expanded posteriorly, some thickening in the region of an iliac (crest) tubercle, a well-developed and knoblike anterior inferior iliac spine that lies noticeably superior to and somewhat back over the superior acetabular rim, a deep greater sciatic notch, differential distribution of cortical bone of the femoral neck, a defined linea aspera, femoral condyles that are of unequal size and different orientations with an outwardly slanted femoral shaft, and a concave lateral condylar facet on the proximal tibia that is at the same level with the medial facet, with the two facets separated by well-developed tubercles. Derived dental features that might unite Hominidae also characterize an orangutan clade. Within Hominidae, various subclades can be justified, suggesting that the relationships of some specimens referred to genusHomolie within a broad ?australopith? clade.