Researchers have pegged a timeline for when the Nullarbor Plain in southern Australia likely shifted into a predominantly arid landscape, according to Curtin University findings. The region, famed for its vast flatness and scarce tree cover, embodies a landscape once translated from Latin as not a single tree. Scientists are keen to pinpoint when this harsh climate became its defining feature because such a transformation reshaped the evolution of Australian flora and fauna in profound ways.
In a focused effort to establish this drying timeline, Maximilian Dröllner and his team examined ancient iron-rich layers buried in the ground. The approach hinges on the need for liquid water to form mineral deposits; by dating each sedimentary layer’s precipitation, researchers can infer the environmental conditions that prevailed when those layers formed. In short, the water story written in the rocks reveals when the landscape became dry.
Findings indicate a pronounced drop in groundwater levels between roughly 2.4 and 2.7 million years ago, aligning with the transition from the late Pliocene’s wetter climate to the early Pleistocene’s drier regime. That climatic shift helped cement a landscape of minimal vegetation and open plains, a signature of the Nullarbor’s modern character that continues to influence regional ecosystems today.
The implications extend beyond geology and climate science. The timing of this aridification offers context for the species that inhabit the southwest and southeast of Australia, where ecological barriers created by ancient climate changes left lineages separated by thousands of kilometers. Zoologists and ecologists see this work as a key piece in understanding how past climate events shaped current biodiversity patterns, including how some birds, insects, and plants trace their common ancestry across distant landscapes.
Previous biologist work has noted intriguing adaptations in local moths, including tail-like structures that may play a role in predator interactions. While those findings add texture to the broader story of Australian ecosystems, the current study focuses on long-term climate-driven forces that organized living communities across vast tracts of land.