Crocodile ecology and the taphonomy of early Australasian sites

Humans and human ancestors have exploited wetland resources for at least two million years. The most significant predators in these landscapes are crocodiles, which leads to two potential taphonomic problems: 1) human-accumulated bones may become intermingled with crocodile-modified bones; and 2) hominins themselves may have been victims of crocodiles. Davidson and Solomon (1990) significantly contributed to this literature through theirsuggestion that a crocodile attack led to the tooth marks on the type specimen of Homo habilis (OH 7) found in Olduvai Gorge, Tanzania. The Australasian tropics were also home to a variety of crocodilian species, crocodile damage to hominin bones being inferred in Trinil and Sangiran, Java. Furthermore, two Pleistocene Australian archaeological sites have stone artefacts in association with crocodile-damaged bone. A referential taphonomic framework is needed to understand the degree and nature of crocodile-hominin interactions on paleolandscapes of Sunda, the ancient Pleistocene landmass incorporating the islands of SE Asia, and Sahul, the Pleistocene landmass of ancient Australia incorporating Papua New Guinea, Australia and Tasmania. This paper provides initial results from crocodile feeding experiments aimed at characterising feeding damage inflicted on bones by the largest extant Australasian crocodile, Crocodylus porosus. Due to close similarity among Crocodylus species in dental and cranial morphology there are some general patterns in the way they modify bones. However, some differences arise when the taphonomic signatures are compared to those of the Nile crocodile (Crocodylus niloticus). We suggest that these differences are attributable to evolved differences in the feeding ecologies of the two species.