New Ages for the Last Australian Megafauna: Continent-Wide Extinction About 46,000 Years Ago

Abstract

All Australian land mammals, reptiles, and birds weighing more than 100 kilograms, and six of the seven genera with a body mass of 45 to 100 kilograms, perished in the late Quaternary. The timing and causes of these extinctions remain uncertain. We report burial ages for megafauna from 28 sites and infer extinction across the continent around 46,400 years ago (95% confidence interval, 51,200 to 39,800 years ago). Our results rule out extreme aridity at the Last Glacial Maximum as the cause of extinction, but not other climatic impacts; a "blitzkrieg" model of human-induced extinction; or an extended period of anthropogenic ecosystem disruption.

A GIS-based reconstruction of late Quaternary paleohydrology: Lake Eyre, arid central Australia

“…They would also have been the last remaining water holes in the catchment as the system dried at the end of a wet interval. This is consistent with the Stage 5a megafaunal remains found in Lake Callabonna (Roberts et al, 2001). Our model suggests that there is a strong likelihood that megafaunal remains of this age would also be found at Lake Blanche, but not at Lakes Gregory or Frome.…”

A new species of Miocene wombat (Marsupialia, Vombatiformes) from Riversleigh, Queensland, Australia, and implications for the evolutionary history of the Vombatidae

“…This is not sur- Results of the phylogenetic analysis with additional species added (relative branching order of these additional taxa are shown here as not resolved) against the geological time scale (Gradstein et al, 2012). Age span of deposits containing all known wombat taxa are provided, with black bars indicating certainty (such as radiometrically dated sites) and grey indicating uncertainty (ages are based on Archer and Wade, 1976;Archer et al, 1989Archer et al, , 1997Archer et al, , 2016Arena et al, 2016;Beck, 2008;Beheregaray et al, 2000;Black et al, 2012b;Cupper and Duncan, 2006;Dawson, 1985;Hope and Wilkinson, 1982;Myers et al, 2001Myers et al, , 2017Piper et al, 2006;Pledge, 1992;Price et al, 2009Price et al, , 2011Prideaux et al, 2010;Vickers-Rich et al, 1991;Roberts et al, 2001;Stirton et al, 1967;Taylor et al, 1994;Tedford et al, 2006;Travouillon et al, 2006Travouillon et al, , 2011Whitelaw 1989Whitelaw , 1991Woodhead et al, 2014). Age of split between taxa is based on oldest possible deposits containing those taxa and as such will change as more information becomes available.…”

Dating the First Australians

“…Black ovals are calibrated 14 C dates from archaeological sites at Devil's Lair, Carpenter's Gap, Riwi, and Mungo; gray squares are archaeological TL/OSL and U/Th/ESR dates from Devil's Lair, Malakunanja II, Nauwalabila I, and Mungo; white ovals are TL/OSL dates from diverse megafauna sites and U/Th dates on Genyornis eggshell. Data from Miller et al (1999), Thorne et al (1999), Fifield et al (2000), Roberts et al (1994Roberts et al ( , 1998bRoberts et al ( , 2001, Turney et al (2001), and Spooner et al (forthcoming).…”

“…Single-grain OSL measurements ) also suggest that there has been disturbance at the site because sediments throughout the sequence contain quartz grains with different optical ages, with the maximum age in Stratigraphic Unit 6 identical to the multi-aliquot OSL result. Roberts et al (2001) studied 28 megafaunal sites using OSL dating of quartz in sediments containing the bones (or attached to bones in museum specimens), and TIMS U/Th dating of flowstones in cave deposits bracketing the most recent occurrence of megafauna. Only sites with articulated skeletal remains in undisturbed deposits were used to estimate an extinction time of 46 ka (95% confidence interval 39.8-51.2 ka) for the flightless bird Genyornis and several genera of large marsupials and reptiles.…”