Taphonomy and paleoecology of the Gondolin Plio-Pleistocene cave site, South Africa.

摘要

This thesis has addressed the applicability of previous taphonomic and paleoecological hypotheses concerning the formation of the hominid fossil record within Plio-Pleistocene South African karstic systems. Prior taphonomic and paleoecological research has often relied on fossil samples with significant sampling, collection, and geographic biases that may have influenced the results of analyses.; Three fossil assemblages from Gondolin have been excavated and/or analyzed here to test previously argued factors that may have influenced the sampled hominid fossil record. The Gondolin assemblages do not suffer from the same limitations that may have restricted the broad interpretations of the fossil samples at other sites.; Comprehensive description, intersite, and intrasite taphonomic and paleoecological analysis has yielded a detailed history for fossil deposits within the Gondolin karstic system. The primary fossil assemblage analyzed here, GD 2, was accumulated in the cave system directly by a felid that used that portion of the cave as a feeding retreat around 1.8 million years ago. In contrast, a fossil deposit in the GD 1 cave region accumulated through the action of both carnivores and porcupines, and was further sorted by an active hydrological system. The paleoecology of the region was (and continues to be) strongly constrained by the local topography, and while likely more mesic during the Plio-Pleistocene; the local distribution of paleohabitats around the site was likely similar to the modern ecosystem.; Comparisons reveal that non-hominid bearing assemblages (e.g. GD 1 and GD 2) are broadly consistent in terms of their reconstructed taphonomy and paleoecology with contemporaneous deposits with significant hominid samples. The results presented here suggested that there were no clear taphonomic or paleoecological trends among sites that can be used to identify the factors that specifically influenced the incorporation of hominid specimens into deposits. Each South African fossil assemblage had a unique taphonomic and ecological history that influenced the composition of the described assemblage. It appears that such diverse (and idiosyncratic) factors as cave geology, primate and predator behavior patterns, and the aggregation and time-averaging of ex situ deposits ultimately mediated the form of the hominid fossil record in South Africa during the Plio-Pleistocene.