Vertebrate trace fossils from the Late Pleistocene of Kangaroo Island, South Australia

Abstract

It is rapidly becoming apparent that the Late Pleistocene vertebrate trace fossil record of southern Australia is much more comprehensive than previously understood, and complements the skeletal fossil record with regard to the distribution of taxa in coastal environments and the palaeobiology of both extinct and extant organisms. We surveyed the majority of prospective Bridgewater Formation outcrops on Kangaroo Island in South Australia and discovered a trace fossil site preserving hundreds of individual traces. A minimum of ten different reptile, bird, and mammal taxa, as well as invertebrates, are represented at the site. Single-grain optically stimulated luminescence dating indicates that the dune in which the traces imprinted was deposited at the beginning of Marine Isotope Stage 5e (135.4 ± 5.9 ka). The traces were made by several extinct taxa including large quadrupeds (most probably diprotodontids), short-faced (sthenurine) kangaroos, and thylacines, as well as extant taxa including possums, the Tasmanian Devil, goannas, shorebirds, and a variety of kangaroos. This site demonstrates that, even though vertebrate trace fossil sites do not often allow the same level of taxonomic differentiation as skeletal fossil deposits, they can nevertheless provide important information about taxon distribution and behavior that can be correlated and contrasted with skeletal fossil assemblages.