Liz Reed has spent the last 20 years digging for answers in the giant underground Naracoorte Caves system in South Australia.
The vertebrate palaentologist, based at the University of Adelaide, wants to know how and when Australia's megafauna died out thousands of years ago.
"This is the ultimate cold case. Hundreds of thousands of years of time, and we're trying to work out whodunnit, if you like. So we record the minute details of the position of each bone, but now we can do that with a laser scanner."
The Naracoorte caves system, she says, holds a rare deposit of fossils.
Their state of preservation and the time period that they belong to makes it unique on a global scale.
The main fossil bed where Dr Reed has spent much of her career is just a few metres under the ground.
More than 130 species have fallen through a hole in the earth above over thousands of years.
And the dry, stable environment of the South Australian Naracoorte caves system has kept them there.
"They've preserved these deposits like tombs that have just been shut, so we see things like completely articulated skeletons of these extinct animals almost where they laid down and took their last breath."
Some of the remains belong to long-extinct species like the marsupial lion and giant kangaroo.
The fossil bed is providing scientists with a near-continuous window into half a million years of life.
Scientists hope soon they'll know a lot more about these creatures and their environment.
A two-million-dollar research grant will see a frenzy of activity over the next four years, led by University of Adelaide researchers and supported by the local council, the South Australian Museum and the state government.
As University of Adelaide PhD student Martin Ankor explains, the funding will help provide new tools to map and date the fossils in incredible detail and shed more light on their history than ever before.
"Laser scanners have been around for a while but in the last 10 years they've really come of age. They allow far more detail to be captured than previous techniques, such as cave surveys, tape measures."
Liz Reed says finding out what happened during mass extinctions in the past could be critically important in preserving species in the future.
"I think it's really important. Extinction is something which is very real today. Many people say we're facing the next wave of extinctions. And the beauty of the Naracoorte deposits we're dealing with mostly animals that are still alive today so if we study those and these lost giants, and see how they responded to climate, and even the arrival of people into Australia, it gives us a window into the future and how we can work to conserving species today."
Naracoorte Lucindale Council Mayor Erika Vickery has been visiting the caves since she was a child.
She's looking forward to the rest of the world discovering their cultural and scientific value.
"I think that we are in an absolutely in a unique position to have the world heritage site here, and now to have this extra research being done which will have a big impact, I think, on climate change knowledge, knowledge of the animals that were here years ago... um, I don't think there are too many communities in the whole world that have this."
The caves can be toured by the public for a fee.
Those who visit will find a half-million-year record of the past, with many more secrets to share.
