Late Quaternary fossil vertebrates of the Broken River karst area, northern Queensland, Australia

Abstract

Two new fossil deposits from caves of the Broken River area, northeast Queensland, provide the first regional records of vertebrate species turnover and extinction through the late Quaternary. Fossil assemblages from Big Ho and Beehive Caves are dominated by small-bodied vertebrates, especially mammals. They represent owl roost deposits, although limited presence of larger-bodied taxa such as macropodids may be the result of occasional pitfall trapping. U-series dating demonstrates that Big Ho dates to the penultimate glacial cycle (c. 165 ka) and Beehive to the early Holocene (c. 8.5 ka). A total of 34 mammalian taxa were identified; within the two deposits, seven taxa are unique to Big Ho and another seven are found only in Beehive. The deposits also preserve five extinct fossil taxa (bandicoots and rodents) that add to a growing list of small-bodied species known to have suffered extinction in the late Quaternary. The deposits further yield the remains of four species of bandicoots and rodents (Chaeropus yirratji, Notomys longicaudatus, Conilurus albipes, and Pseudomys gouldii) that suffered extinction post-European colonization. These new fossil records represent significant increases in the known geographic and temporal range of several species and begin to fill an important gap in our understanding of the faunal history of tropical northeast Australia.