Hopes for Underwater Fossils to Reveal Prehistory

By Josh Brine

ABC South East SA

Fossils

Thursday, 16 July 2026, 7:01 am

Fossils are found on the bottom of a sinkhole.

In short:

New research from Griffith University helps us understand when and why bones are in underwater caves.

The study also looked at how bones in underwater caves stay in good condition.

What's next?

The researchers hope their work will help us learn more about fossils in underwater caves.

The researchers want to use fossils to learn about the past.

The study looked at how the environment in underwater caves affects fossils.

PhD candidate Meg Walker said we don't know much about fossils in these caves.

Meg Walker said the caves were dry in the past.

If we can link fossils to dry or wet periods, we can learn about the animals that lived then.

Meg Walker looks at fossils from Engelbrecht Cave.

The research team went to Mount Gambier to study fossils.

The results can help us understand fossils in other places.

There are many fossils in Mexico's cenotes.

Many studies just report finding fossils, but don't analyze what they mean.

Professor Julien Louys explores Kilsby Sinkhole.

A look back in time

The team found animal bones in Green Waterhole and Gouldens Sinkhole.

The bones are from cows, kangaroos, and other animals.

Gouldens Sinkhole is a big cave with steep sides.

Green Waterhole is like a tunnel with a big open area.

The cave-diving team in Gouldens Sinkhole.

The team learned how the underwater cave environment preserves bones.

Bones in dry areas are exposed to weathering and bacteria.

In underwater caves, bones are not exposed to weathering and bacteria.

As you go deeper into the cave, there are no aquatic bacteria.

Meg Walker and Professor Julien Louys are cave divers.

Joseph Monks has worked with Professor Louys for seven years.

They found thylacoleo teeth and maybe a den.

Much of this is hard for cave divers to understand.

A palaeo-reconstruction of fossils in a South Australian cave.

The team decides which bones to recover.

These caves are very old, 30,000-50,000 years or more.

When we touch things in the cave, we change it forever.

We must think carefully about whether it's worth recovering a fossil.

Sometimes fossils are easy to find, like in a museum.

Meg Walker sorts through fossil bones.

Filling in the record

The bones from this study are from the past 100-200 years.

Fossils in underwater caves can help us learn about the past.

The World Heritage Naracoorte Caves have a lot of information.

But the record is not complete, and we are limited by preservation.

We are piecing together the story of the cave.

New species are being found in the Green Waterhole.

Some fossil fragments have been hidden for thousands of years.

Hopefully, we can use this information to understand species and extinctions.

The work in South Australia is leading the way.

The cave system in South Australia is pristine and accessible.

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Thursday, 16 July 2026, 7:01 am

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