Reconstructing the Habitats of Australopithecus: Paleoenvironments, Site Taphonomy, and Faunas

Hominin paleoecology is reconstructed using many types of evidence from fossils and their geological context. This evidence is limited by vagaries of the fossil and geological record. What questions can be asked regarding Australopithecus ecology given these limitations? We address this topic by reviewing the major issues concerning hominin synecology and taphonomy and discuss methods for deriving ecological information from fossil assemblages and their geological context. We provide basic information about the context of the six Australopithecus species known from 22 collecting sites and review their environment of deposition and other paleoecological evidence. Using this information we attempt to answer a series of questions, such as whether we can determine the habitat preferences of the different species, and whether more than one Australopithecus species shared an ecosystem at any given place and time. We conclude that Australopithecus as a genus was eurytopic because of the wide range of well-documented habitat reconstructions, but only Australopithecus afarensis, and possibly Australopithecus anamensis, have enough time range and fossil material to support the interpretation that these species were eurytopic. The dietary differences between east and south African species are intriguing given microwear analyses differentiating the two groups, although the carbon isotope data are similar. Further evidence of the ecological context of these species is needed and should be standardized using an appropriate scale of evidence (temporal and spatial) for the desired scale of habitat reconstruction.