The late Quaternary crocodylian record from Australasia

Abstract In this study, we synthesize the known late Quaternary crocodylian record in Australasia through literature review and direct assessment of fossil and zooarchaeological material. The late Pleistocene record, mainly from Australia, consists of partial skeletal remains mostly referable to the extinct Mekosuchinae, with some attributable to Crocodylus. The youngest reliably dated mekosuchine fossil is ∼20 000 years old, suggesting mekosuchine decline and extinction coincided with that of other Australian megafauna. In contrast, three south-west Pacific islands—New Caledonia, Vanuatu, and Fiji—were Holocene refuges for mekosuchines, whose remains occur in archaeological contexts, indicating human interaction. Their extinction followed soon after human arrival, suggesting anthropogenic influence as a potential key factor. Crocodylus johnstoni occurs in palaeontological (potentially 28 kya) and archaeological sites in Australia. Crocodylus porosus has an ambiguous fossil record potentially going back over 40 kya, but is definitively present by the Holocene. Most Crocodylus remains come from coastal sites overlapping modern ranges. Archaeological evidence supports crocodile utilization by humans in Australia, Torres Strait, and New Guinea. The fragmentary nature of the known fossil material, as well as the current lack of reliable dates, leaves many unanswered questions about the morphology, palaeobiology, and disappearance of mekosuchines.