Homo erectus palaeoecology in Java: A study of cervid post-cranial ecomorphology

Abstract

This dissertation reports on the palaeoenvironmental reconstructions of several Pleistocene sites from Java (mainly Trinil, Kedung Brubus and Sangiran), based on newly developed ecomorphological methods for the cervid calcaneus and intermediate phalanx. Using a geometric morphometrics approach, 3D-landmark data were collected on extant cervids of known habitat preference, to establish correlations between morphological traits, locomotor behaviour and environmental parameters. These models were then applied to deer fossils from the selected sites to assess past vegetation structure and substrate type.

This study extends the suite of ecomorphological methods available for palaeoenvironmental reconstruction. The morphology of the calcaneus and intermediate phalanx were found to vary with locomotor strategy and habitat along a continuum from open habitats with dry substrate to closed habitats with wet substrate. Furthermore, this dissertation contributes to our understanding of the understudied Pleistocene environments of Java. The results of Trinil confirmed interpretations of an open woodland, but suggested a relatively wet substrate. The results of Kedung Brubus and its associated fauna indicated open, but drier conditions and presumably coincided with a glacial stage when Java was connected to the Asian mainland, allowing increased biotic interchange with the continent. The material from Sangiran suggested open conditions, and either dry or wet substrates, possibly reflecting the mixed nature of the assemblage.

The early dispersal of Homo erectus, considered the first hominin to have expanded its biogeographic range over large parts of the Old World, is generally hypothesized to have been more driven by either extrinsic (e.g. the expansion of open environments) or intrinsic factors (e.g. the increased capacity of H. erectus to adapt to variable conditions). The reported palaeoenvironmental reconstructions provide an estimate of the extent to which this species depended on a specific type of environment. The results do not contradict a scenario where Homo erectus was restricted to more open environments for its survival and dispersal. A significant degree of environmental flexibility can, nevertheless, be extrapolated from its presence in dry and wet conditions, and in areas with different vegetation structures ranging from grassland to open woodland.