Unveiling the Mysteries of Mt Gambier's Submerged Fossil Deposits

Abstract

Cutting-edge technical diving and scientific exploration in the flooded caves of Mt Gambier, South Australia, has the potential to illuminate the mysteries of Australian megafauna extinctions and faunal interactions in unique underwater contexts. Studying the submerged fossil and faunal deposits of the region can not only uncover past ecosystems but also offers a rare opportunity to characterise taphonomic and diagenetic processes on bones deposited by European settlement post-1788. The recovery of European domesticate bones from sinkholes and underwater caves provides not only a rare resource to understand faunal deposition in flooded settings, but is also providing surprising results regarding European impacts on local ecosystems. Notably, a jawbone extracted from Gouldens Hole, a renowned dive site, was identified as a very early example of sheep on the Australian mainland. Its identification is confirmed by ZooMS analysis. Intriguingly, four radiocarbon dates derived from the premolar and molar suggest the sheep's demise as early as the 1740s, potentially extending to 1814, a timeline that could predate known European settlement of the region. Such a finding opens intriguing possibilities: the sheep might signify an early incursion from New South Wales or be remains of animals left on the coast to assist marooned sailors. Regardless of origin, it indicates an early sheep presence, with concomitant ecological impacts, in South Australia. This presentation underscores the fusion of technical diving skills, scientific rigor and exploration, spotlighting submerged caves as portals to deep and near-time history.

About the Presenter

A/Prof Julien Louys is Deputy Director of the Australian Research Centre for Human Evolution and Principal Research Fellow specialising in the development of analytical methods of environmental reconstructions using the mammalian fossil record.

Meg Walker is a PhD Candidate at Griffith University, focusing fossil assemblages from the underwater cave environments at Mount Gambier, South Australia. With a background in archaeological and evolutionary sciences from the ANU, she aims to investigate past environments and bone biology in archaeological and palaeontological contexts.

Joseph Monks is a qualified diver of 15 years’ experience, completing hundreds of dives in Australia and around the world. He has been involved in various projects involving science, mapping & surveying, and recreation of underwater caves, including coordinating and leading multiple cave diving exploration trips to the Nullarbor region in Western Australia, Queensland, and New South Wales.