3D Morphometric Study of the Mandibular Fossa and Its Implication for Species Recognition in Homo erectus

The problem of species recognition in paleoanthropology has been the subject of numerous studies. In the current study, we have used the complex topography of the mandibular fossa to assess its potential as a species-specific indicator. Six landmarks were registered using a microscribe 3Dx digitizer on four extant species: Pan paniscus, Pan troglodytes, Gorilla gorilla, and two ethnical groups of modern humans. Using principal component analysis (PC), the results statistically separated between the species and within the two Homo groups. The same method was applied to a sample of 13 casts of Pleistocene hominids from Asia, Europe and Africa. The first PC separated Asian Homo erectus from African Homo erectus and Homo heidelbergensis. The second PC separated African Homo erectus from Homo heidelbergensis. Interestingly Homo floresiensis groups with Homo heidelbergensis. Adding recent human sample to the analysis showed them to fall within the African Homo erectus group. Cluster analysis on the superimposed fossil data had turned the same results. These results favor the view that Homo erectus is actually made from at least two distinct species. Homo floresiensis is not a form of pathologic sapiens, and Homo sapiens has descendent solely from early African-like species.