The chronology and environmental context of a cave deposit and associated faunal assemblage including megafauna teeth near Wee Jasper,southeastern Australia

Abstract

A limestone cave on the lower slopes of the southeastern Australian high country reveals a deep, stratified deposit dated from ca. 14,000 to 2000 cal. BP and rich in predominantly non-cultural faunal remains. Located in a sensitive ecological area between the Australian Alps and the Southern Tablelands, the site provides a valuable chronological archive for the interpretation of local environmental change using the faunal record as a proxy, in particular native rodents and other small mammals. Inferred palaeoenvironmental trends include the cessation of periglacial conditions in the surrounding ranges during the Terminal Pleistocene; a shift to warmer conditions and the establishment of forest and wetland habitats from around 13,500 to 10,000 cal. BP, with a significant decline in cold-adapted species at ca. 11,500 cal. BP and a period of significant taxon fluctuation and extinctions corresponding to a possible peak in warm and moist conditions (a ‘Holocene Optimum’), beginning around 8000 cal. BP and lasting perhaps 1500 to 2000 years. Complications to the relatively steady and continuous chronostratigraphy, formed from an AMS radiocarbon sequence from sedimentary charcoal, arose from the presence of several teeth of extinct sthenurine megafauna. These were resolved with direct U-series analysis to establish their much greater antiquity and comparison of the sthenurine teeth with teeth of extant macropodids from the same deposit through fluoride absorption analysis, which also identified the megafauna teeth as anomalous to the sequence. The site provides an important case study for the interpretation of megafauna remains in stratified sedimentary deposits, especially for sites that appear to contain evidence for the co-occurrence of megafauna and humans in primary contexts.