Hominin paleoecology and cervid ecomorphology

Abstract

Homo erectus (senso lato) was a remarkable hominin in that it was the first hominin to have a biogeographic distribution throughout the Old World. While there are many hypotheses regarding why Homo erectus dispersed into Eurasia when no other hominin before had, this dissertation focused on those hypotheses concerning extrinsic environmental influences. There were four main goals of this study: 1) to establish habitat reconstruction methods using ecomorphology for the family Cervidae (deer and relatives), 2) to introduce geometric morphometrics to studies of ecomorphology in paleoanthropology, 3) to expand ecomorphological methods that can be conducted upon incomplete bones, and 4) to apply the methods introduced here to four Eurasian fossil sites. Ecomorphological methods have been established for the Bovidae, but methods for Cervidae, often the most abundant taxon in Eurasian paleoanthropological assemblages, are lacking. Cervid morphology as it relates to adaptations to habitats was analyzed here for four skeletal features using 3D geometric morphometrics (GM). GM was particularly suited to this study because it allowed for quantification of morphology that previously had been evaluated qualitatively. Further, shape variation associated with different habitats and substrates was visualized, allowing for recognition of subtle variations in morphology. Two joints surfaces of extant cervid femora and tibiae, in addition to the entire calcaneus and the plantar morphology of the third phalanx, were analyzed here using canonical variates analysis. Morphology of the calcaneus was found to vary with habitat along a continuum from open to closed vegetational structure. The femoral and tibial joint morphology was more discreet in variation, having closed and non-closed variants. Plantar morphology of the third phalanx was found to reflect substrate type and varied on a continuum from more dry to more wet substrates. The methods introduced here were applied to four Plio-Pleistocene fossil sites. Though only one of the four sites (`Ubeidiya, Israel) contained hominin remains, all four were reconstructed to have been open to intermediate open habitats. These reconstructions are broadly similar to contemporaneous African and Eurasian hominin sites, and thus, habitat type did not preclude hominin occupation of Valea Graunceanului (Romania), and St. Vallier and Senèze (France).