Human occupation of northern Australia by 65,000 years ago

Abstract

The time of arrival of people in Australia is an unresolved question. It is relevant to debates about when modern humans first dispersed out of Africa and when their descendants incorporated genetic material from Neanderthals, Denisovans and possibly other hominins. Humans have also been implicated in the extinction of Australia's megafauna. Here we report the results of new excavations conducted at Madjedbebe, a rock shelter in northern Australia. Artefacts in primary depositional context are concentrated in three dense bands, with the stratigraphic integrity of the deposit demonstrated by artefact refits and by optical dating and other analyses of the sediments. Human occupation began around 65,000 years ago, with a distinctive stone tool assemblage including grinding stones, ground ochres, reflective additives and ground-edge hatchet heads. This evidence sets a new minimum age for the arrival of humans in Australia, the dispersal of modern humans out of Africa, and the subsequent interactions of modern humans with Neanderthals and Denisovans.

The Cranebrook Terrace revisited: recent excavations of an early Holocene alluvial deposit on the banks of the Nepean River, NSW, and their implications for future work in the region

“…The Richmond Unit is a ~20 m deep sedimentological body composed of a basal gravel bed, overlain by a sandy clay overburden, dating to ~40-50 ka and ~15-20 ka, respectively (Stockton and Nanson 2004;Mitchell 2010), with all other parts of the terrace > 50ka and generally beyond the accepted colonisation age of Australia (O'Connell and Allen 2015; cf. Clarkson et al 2017). This model thereby provides greater support for the findings of the 1970s and 80s with the artefacts recovered from the base of the Richmond Unit, and a reason why some later investigations (in the Penrith Unit) failed to find any archaeological material.…”

Invasive species and their impacts on agri-ecosystems: issues and solutions for restoring ecosystem processes

“…These were followed by rodent members of the Muridae during the late Miocene, leading to the evolution of 66 native species present in 1788. Humans arrived at least 65 000 years ago (Clarkson et al 2017) and what invasive passengers and chattels they brought with them is unknown. People were also responsible for the introduction of dingoes, an ancient breed of Canis familiaris introduced from South-East Asia~4500 ybp (Jackson and Groves 2015;Jackson et al 2017), that subsequently became feral (Fleming et al 2014) and invaded most Australian environments (Johnson and Letnic 2014).…”

Early signs of human presence in Australia

“…But despite more than 80 years of research on the quantum theory of electronic motion in solids and the impressive capabilities of devices such as the modern smart phone, there remain gaps in our knowledge. In a conceptual breakthrough, Bradlyn et al 1 report on page 298 a theory that combines aspects of both chemistry and physics. The theory improves our understanding of known materials and can be used to search for materials that have previously undiscovered electronic properties.…”

“…After calibration, the amount of luminescence released can indicate how long the sediment sample has been buried. Clarkson et al 1 used this technique, known as optically stimulated luminescence, to provide a revised timeline for human occupation at the archaeological site Madjedbebe in Australia, revealing that humans reached the continent earlier than previously thought.…”

“…Just as palaeontologists use fossilized skeletons to make inferences about the appearance, diet and behaviour of dinosaurs, astrophysicists are beginning to use gravitational waves from compact stellar remnants to explore the lives -and deaths -of massive stars. ■ 1 report an analysis of archaeological fieldwork in Australia, and propose a revised timeline for the peopling of this continent.…”