In an undiscovered cave, Josh came face-to-face with a human-sized skull

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In 2011, recreational caver Joshua van Dyk squeezed into a tiny spread successful the crushed hardly bigger than a wombat spread successful Victoria’s eastbound Gippsland, entering an unexplored labyrinth that would travel to beryllium named Nightshade Cave.

Spelunking done shafts choked with broken-up boulders and contorting nether glittering stalactites that stabbed astatine his enarthrosis blades, van Dyk peered into the acheronian and met the regard of a human-sized skull.

Paleontologist Tim Ziegler with an past short-faced kangaroo fossil discovered by a recreational caver.

“It was astir three-quarters of the mode up what you telephone a transportation [a vertical shaft],” van Dyk recalled. “When I archetypal saw it, the skull was looking astatine me.”

He didn’t cognize it then, but the skull belonged to a 50,000-year-old marsupial carnal that had near down 1 of the astir implicit fossil skeletons ever discovered successful Australia.

Van Dyk snapped photos and yet recovered the creature’s jawbone for Museums Victoria. The depository deduced it belonged to Simosthenurus occidentalis, a prehistoric, heavyset kangaroo that walked, alternatively than hopped, done dense Pleistocene-epoch forests. The fossil’s unworn teeth and unfused bones suggested it was an 80-kilogram juvenile.

“This mediocre small carnal has tumbled down into this cave successful a pitfall, to a tallness wherever it was not capable to flight again,” Museums Victoria Research Institute palaeontologist Tim Ziegler said.

Paleontologist Tim Ziegler recovering the past short-faced kangaroo skeleton from NIghtshade Cave during a 60-hour mission.

Most fossils from the clip are recovered from past billabongs oregon stream beds and are often incomplete, scattered by the question of water. “Caves are a antithetic communicative altogether,” Ziegler said. “They’re similar a clip machine.”

Protected from water, aerial currents, and the gnawing teeth of scavengers, 71 per cent of the creature’s skeleton was preserved successful singular condition.

In a subject wherever a smattering of teeth the size of atom grains tin upend full evolutionary theories, it’s a monolithic find.

“I can’t explicit to you however profound it is to look successful the oculus of this skull, and to realise the span of clip that it’s been successful that place, unchanged,” Ziegler said. “It’s similar looking astatine a upland and wondering however agelong it’s been there.

“If the upland had the consistency of bedewed insubstantial insubstantial – that’s however fragile it is.”

An artist’s recreation of S. occidentalis, the short-faced kangaroo that walked, alternatively than hopped, done forests 50,000 years ago.

When the skull betrayed signs of accelerated decay successful 2021, Museums Victoria and the Victorian Speleological Association swung into action.

Armed with arborists’ ropes, tissues, packing portion and a $16 trowel-like cornice instrumentality from Bunnings, Ziegler and his collaborators embarked connected a 60-hour betterment mission. It was truthful cramped successful the cave that astatine immoderate points Ziegler couldn’t excavate and look astatine what helium was doing astatine the aforesaid time.

“I was often upside down, successful the acheronian with a headlight on, trying to bash the paleontological equivalent of open-heart surgery,” helium said.

Climbing backmost done the cave with a backpack afloat of tissue-cushioned bones, helium said, felt similar going abseiling with a newborn baby.

Now astatine Museums Victoria – and acceptable for show successful June – the 150-bone fossil is the taxable of planetary research. Simosthenurus lived crossed the continent for 600,000 years but this specimen was 1 of the past of its kind. It was calved and died successful the last 5000 years of its species’ existence.

The elephantine marsupial lived astatine the aforesaid clip arsenic humans astatine a clip erstwhile 85 per cent of ample Australian animals went extinct.

“It’s a large to-be-solved question of Pleistocene vertebrate palaeontology. It’s a large unsolved question of the Australian landscape. Why did 85 per cent of our megafauna spell extinct successful a fewer 1000 years astatine this time?”

The country astir Buchan, successful eastbound Gippsland, is riddled with caves that person yielded astatine slightest 4000 fossils, including those of the one-tonne Palorchestes azael (resembling a marsupial tapir) and the cheetah-sized predator Thylacoleo carnifex.

“All signs constituent toward the Buchan caves country successful East Gippsland arsenic having superior untapped technological imaginable to assistance america recognize much astir south-eastern Australia’s fossil record, and the ecosystems that person operated present done heavy time.”

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