Comparative Taxonomic, Taphonomic and Palaeoenvironmental Analysis of 4-2.3 Million Year Old Australopithecine Cave Infills at Sterkfontein.

[摘要] The site of Sterkfontein is rich in fossil deposits spanning different time periods fromas early as 4 million years to as recent as 116, 000 years. Stratigraphy, taxonomy,taphonomy, archaeology and palaeoenvironmental analysis from various infills have beenunder constant review as new materials are recovered from the ongoing excavations. It is therecovery of numerous new fossils that prompted a need for a review into earlier hypotheses,interpretations and conclusions arrived at by earlier researchers on the Member 4 and theJacovec Cavern infills.New data indicates that the two infills, though spanning different time periods, sharesimilarities but also display marked differences in taxonomy, taphonomy andpalaeoenvironment. Taxonomically, the most striking difference between the two deposits isthe higher frequency of taxa and species diversity within the Member 4 faunal assemblagethan in the Jacovec Cavern faunal assemblage. There are nine bovid tribes represented in fivesubfamilies within Member 4 and six bovid tribes in three subfamilies within JacovecCavern. At least five primate species have been recovered from Member 4 while threeprimate species have been recovered from the Jacovec Cavern. Twelve carnivore species arerepresented in Member 4 while eleven are represented in Jacovec Cavern. Some categories ofother fauna are limited to the Member 4 infill while others are limited to the Jacovec Caverninfill.Taphonomically, both assemblages are characterized by low frequencies of bonemodification. These low frequencies are a result of a culmination of various agents ofaccumulation and varieties and intensities of postdepositional processes that impacted on theoriginal deposited assemblage prior to recovery. The faunal assemblage in Member 4 wasaccumulated into the cave through a combination of voiding carnivores, 'death trap” and natural death within the cave. The Jacovec Cavern fauna on the other hand was accumulatedby carnivores, not in the cavern but on the surface above and within the vicinity of the caveentrance. Eventually fluvial action incorporated the surface materials, including faunalremains into the Jacovec Cavern.Palaeoenvironmental reconstruction indicates a correlation of climatic conditionssimilar to that derived from analysis of terrigenous sediments off the coast of Africa. ForMember 4, palaeoenvironmental reconstruction indicates the existence of a mix of forest andopen savannah with more emphasis on woodland, while a mosaic of open grassland anddense forest, equivalent to today’s tropical forest in Africa is suggested for the JacovecCavern.

[发布机构] University of the Witwatersrand