Fossil hunters in Australia have discovered a cave filled with the remains of marsupials that lived 15 million years ago.
The rare haul of fossils includes 26 skulls from an extinct, sheep-sized marsupial with giant claws, the BBC reports.
The beautifully preserved remains from the Riversleigh World Heritage fossil field in north-west Queensland have been described in the Journal of Vertebrate Paleontology.
"It's extraordinarily exciting for us," says University of New South Wales palaeontologist Mike Archer, co-author of the research. "It's given us a window into the past of Australia that we simply didn't even have a pigeonhole into before.
"It's an extra insight into some of the strangest animals you could possibly imagine."
Palaeontologists have been stunned at how well preserved the fossils were - and by how many were found.
But how the animals all ended up in the cave remains a mystery. One theory is that they accidentally plunged into it through an opening obscured by vegetation and either died from the fall or became trapped and later died.
