Cave “Fingerprints” Reveal How Bones Preserve Underwater

Researchers at Griffith University in Australia examined bones from two underwater cave systems, Green Waterhole and Gouldens Sinkhole, to understand how submerged environments preserve skeletal remains. The team, led by PhD candidate Meg Walker, analyzed bone surfaces and chemistry at both macro and micro levels, using radiocarbon dating to establish a timeline.

They discovered that underwater caves create unique “preservation fingerprints” distinct from dry caves. Bones near cave entrances exhibit signs of plant and algae growth, while those deeper inside remain more pristine due to constant darkness.

Dry caves showed alteration from bacteria and root growth instead. The study included remains from animals like kangaroos, cows, and dingoes, some potentially dating back to the 1840s. This new framework for interpreting bone deposits will help archaeologists and paleontologists reconstruct past environments and better understand how megafauna fossils became preserved underwater.