A new unnamed species of endemic Australian crocodile has been identified in the middle of the outback.
The species of the now-extinct crocodile, which belongs to the Baru genus, is new to scientists despite the creature wandering the Australian continent 25 million years ago.
Senior curator of earth sciences at the Museum and Art Gallery of the Northern Territory Adam Yates said that Australia's best example of the crocodile's skull was found in 2009 at the Alcoota Fossil site, 200 kilometres north-east of Alice Springs and is eight million years old.
Dr Yates said other specimens had been found at earlier times.
"This particular specimen is one of the last of its kind. It is by far the nicest and most complete skull of a Baru crocodile that's ever been found," he said.
Thanks to the condition of the skull, Dr Yates said that it would become the name-bearing specimen or what he called "the holotype" of the new species.
Not related to modern crocodiles
Dr Yates said that the modern Australian crocodile had the reputation for being ancient and unchanging, but that was not actually true.
"The Australian crocodiles are actually recent arrivals on the Australian continent. They belong to the genus Crocodylus, which probably has an origin in Africa," he said.
Dr Yates said this type of crocodile immigrated and colonised Australia only a few million years ago.
"Whereas Australia's original endemic crocodiles like this one, have gone extinct completely," he said.
Dr Yates said the size of this Baru was comparable to a modern saltwater crocodile, however, given the robusticity of the skeleton it would have been heavier.
"It probably weighed more than an equivalent length to a saltwater crocodile. So we're looking at many hundreds of kilos," he said.
By studying the skull in detail it will provide clues not only to the changing state of Australia's environment but also how this particular crocodile differs from other known species.
"We have to get down to the nitty-gritty of its anatomy, and demonstrate why this one's anatomy is a little bit different from all the other known species of ancient crocodile from Australia," he said.
Dr Yates said the size of the skull indicated that the creature was very strong.
"Its really strongly built thick, heavy, deep jaws, and really massive teeth all indicate that this was a crocodile that was specialised in taking megafauna," he said.
"[Modern crocodiles] subsist mostly on small fish and small prey. This guy didn't subsist on small things.
"It was specialised for taking big things - all the time."
Dr Yates said modern saltwater crocodiles were also capable of taking larger animals.
One bird that Baru hunted was Dromornis stirtoni, a large flightless bird that stood about 3-metres tall and weighed up to 650 kilograms.
"We know from other sites that Baru was tackling Dromornis because we found Dromornis bones with crocodile-teeth puncture marks in its leg bones," he said.
The new species name is expected to be unveiled in 2022.