Reconstructing the Habitat Mosaic of Australopithecus robustus: Evidence from Quantitative Morphological Analysis of Bovid Teeth

Abstract

This research better resolves the environmental mosaic that is typically reconstructed for the A. robustus-bearing faunal assemblages of South Africa and evaluates whether A. robustus were habitat specialists or habitat generalists by testing whether they are associated with numerous, different reconstructed habitats, or if they can be associated with a single, more homogeneous habitat type. Determining the habitat preferences of A. robustus holds important implications for understanding the behavior of these hominins and, potentially, for understanding whether their ultimate extinction might have been climatically influenced, as fluctuations in the environments associated with the robust australopiths provide direct evidence about the responses of hominins to environmental change. To achieve this, a 2-dimensionsal morphometric tool was developed for accurately identifying the abundant bovid teeth that are found in direct association with the hominins using Elliptical Fourier Function Analysis. More accurate taxonomic identifications facilitate more precise estimates of the relative abundance of ecologically sensitive bovids, allowing for finer resolution when segmenting the various components of the reconstructed habitat mosaics. The fossil bovids abundances were compared across the assemblages over time in order to define the environmental mosaic in each assemblage and to determine if environmental heterogeneity existed across the assemblages. The relative abundances of the bovid fossil assemblages and A. robustus were compared to assess the habitat preferences of these hominins. A. robustus were not consistently associated with a particular habitat type suggesting that perhaps they were habitat generalists, capable of surviving in multiple types of habitats.