These days the Nullarbor Plain is a vast, treeless expanse. However, travel back in time far enough and you would find it teeming with life.
What types of creatures once roamed the plain many years ago? There was, in fact, a diverse menagerie of creatures that included giant cuckoos and terrifying marsupial lions.
Many of the best fossil discoveries are found in caves within the earth, as it is thought that the animals would go there to lay down and die. The dry and dark conditions with the subterranean pockets are perfect for preserving the remains.
When paleontologists have gone searching in these caves, they have uncovered a treasure trove of fossil remains – which have given them a glimpse into the bizarre creatures that once lived in this region.
One of the best discoveries was in a location known as Leaena’s Breath Cave. It has a small hole mostly covered with vegetation, which opens up to a large void below. Many animals accidently fell into the cave and died, their skeletons kept there in perfect condition for hundreds of thousands of years. To enter the cave, scientists had to wriggle through a 10 meter long tunnel and then carefully lower themselves through a 15 meter drop to the floor of the cave.
So what kind of animals used to live in the Prehistoric Nullarbor?
Imagine a creature with huge claws and a powerful bite that is the size of a leopard, yet has the body shape of a bear and is able to stand on its hind legs like a kangaroo. It sounds like a made-up fantasy animal – but it actually existed long ago on the Nullarbor Plain.
This strange and fascinating beast is a Thylacoleo Carnifex – or a marsupial lion. Although it is a marsupial, it has a closer relationship biologically to the cat family. For example, it has retractable claws like a cat – which is a trait never before seen in marsupials.
A near-complete skeleton was found by paleontologists on their fifth expedition to Leaena’s Breath, Last Tree Cave and Flightstar on the WA side of the Nullarbor. These caves are rich with fossils and over 100,000 bones have been collected there during past visits.
The Thylacoleo Carnifex lived in Australia from the late Pliocene to the end of the Pleistocene period – a period of time stretching from two million to forty-six thousand years ago. These creatures would have been the largest mammal predators on the continent at that time, weighing approximately as much as a small lion. Pound for pound, they had the most powerful bite of any mammal that has ever lived.
A 2014 archeological dig at the Thylacoleo Caves also found that the Nullarbor was once home to a group of birds that are known as “Coucals.” They are part of the cuckoo family and they would have stood more than half a metre tall. Judging by the density of its bones, it was likely flightless.
There are 26 living species of coucal that still exist today, but only one living species resides in Australia – the Pheasant Coucal. It makes its home in the north and east of the country. Without this recent fossil discovery, we would have never realised that the ancient relatives of modern coucals lived so far south in Australia.
Coucals are not like typical cuckoos. For example, cuckoos are known for sneaking their eggs into the nests of the other birds in order to trick them into raising their young. However, coucals don’t do this – they build their own nests and are responsible for their young.
Coucals are also unusual because the females are larger than the males and the males primarily do the work of raising the brood. This is a trait that is only shared with 5% of the world’s bird species.
It’s hard to imagine a tree kangaroo dwelling in a region that is currently so flat and treeless. The name Nullarbor even means “without trees” in Latin. However, the climate and conditions of the area have undergone a lot of changes since the Pleistocene period when these creatures were alive.
The tree kangaroo fossils found on the Nullarbor plain are of the extinct genus Bohra and they were preserved in caves. They are close to the tree-kangaroo genus Dendrolagus and they are also similar to rock-wallabies. This seems to confirm the recent studies that are suggesting rock-wallabies and tree-kangaroos share a common point of ancestry.
A Wombat the Size of a Small Car
Ok, now I’m sure you probably thinking that I’m getting a bit too ridiculous – but truth really is stranger than fiction. Fossil remains of Diprotodon Optatum have been discovered on the Nullarbor Plain, which is a giant wombat-like animal that was larger than a hippopotamus. There is a theory that the Diprotodon is the origin of the legend of the bunyip from Australian aboriginal mythology.
Experts believe that the Diprotodon Optatum weighed approximately 6,142 pounds. It existed from around 1.6 million years ago, until it went extinct 46,000 years ago. The theory is that when human hunters emerged, they killed and ate these giant wombats – causing their extinction.
These are just a few examples of the fascinating animals that used to make their home here many thousands (and even millions) of years ago. If you want to learn more, check out this National Geographic photo gallery with images from the expedition.