Take a walk along the right beaches on the southern Australian coast and you can leave your footprints next to those of ancient creatures that walked the same path thousands of years before you.
A recent expedition has uncovered one such site on Kangaroo Island. There on the ground is the evidence of the prehistoric marsupials that walked, skittered and hopped along these parts during the Ice Age.
For years, a group of researchers has been engaged in a project surveying the coastlines of southern Australia, and it was in 2011 that Kangaroo Island locals drew their attention to a beach on Dudley Peninsula. There, hundreds of footprints were waiting to be examined.
"Australian fossil vertebrate trackways are extremely rare and this project was the first of its kind in Australia," said Dr Aaron Camens of Flinders University, who is part of the research team.
The footprints range from a mere (geologically speaking!) 20,000 years old to at least 200,000 years old, during the end of the Pleistocene Epoch. They represent at least a dozen species, including many that no longer exist on the Australian mainland.
Among the extinct marsupials who left their marks on the site were thylacines (or Tasmanian tigers), which – despite the occasional wishful sighting – are thought to have disappeared from mainland Australia at least 2,000 years ago. There are also footprints of ancient short-faced kangaroos (which probably walked instead of hopping!), and a two-ton, four-legged beast called Diprotodon, the largest marsupial of all time.
But it wasn't just extinct animals who walked here. The footprints also reveal the presence of ancient Tasmanian devils, which haven't lived on the mainland for thousands of years, as well as quolls, which can still be found in fragmented pockets across the continent. Both of these marsupials have suffered serious declines in recent decades due to habitat loss and the threats posed by invasive species.
Also among the footprints at the site are the tracks of birds, lizards, possums, various other kangaroos and invertebrates. And that's just the ones that have been identified! So far, more than 300 prints have been found, but the researchers say there are more to come.
Finding fossil footprints can be very exciting, and they can offer palaeontologists information that the skeletons of ancient creatures can't always provide. "They can show us elements of the animals' behaviour … how they interacted with each other and what kind of environments they moved through," Camens said in a report from the university.
And there's more. The fact that these trackways span tens of thousands of years will allow palaeontologists to examine how these animals changed over time. This chunk of geologic history brought major fluctuations in climate, and Kangaroo Island itself was alternately connected and separated from the mainland as sea levels rose and fell. It was a time of major extinctions, too. Clues to how these species reacted to all of this upheaval may lie hidden among their petrified foot impressions.
Many of these traces have already been casted for study. In some cases, the researchers are even using specialised software to create 3D models of the trackways.
Australia is a bit of a hotbed for fossils of all ages. This Ice Age stomping ground joins the likes of the Jurassic walkway in Western Australia, which preserves some of the world's largest dinosaur footprints, as well as the fossil sites of the Flinders Range in southern Australia, which preserve half-a-billion-year-old fossils of some of the world's earliest animal life.
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Top header image: Yun Huang Yon/Flickr
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