Australia's newest species of armoured dinosaur sported a parrot-like beak and inner ear similar to a turtle.

Kunbarrasaurus ieversi, or Kunbarrasaurus, appears to be a primitive ankylosaur, a group of four-legged herbivorous dinosaurs known for their heavy armour and club-like tail.

The remarkably well-preserved fossil skeleton, which even includes details such as skin texture and stomach contents, was discovered back in 1989 in Richmond, Queensland.

The skeleton was originally thought to be the same genus as Australia's only other ankylosaur — Minmi.

But after two decades of work to prepare the fossil for study, researchers have concluded it is not only a different species, but an entirely different genus of ankylosaur.

In this study, published today in PeerJ, researchers used CT scanning to examine the dinosaur's head and brain, which revealed the features that distinguish this from other ankylosaurs found elsewhere in the world.

"One of the most unusual things about it is the osseous labyrinth of the inner ear," University of Queensland palaeontologist Dr Steven Salisbury said.

"They are huge; they are so different to anything else we've seen before we can't really make any sense of them."

These most closely resemble the inner ears of modern tuatara reptiles but Dr Salisbury said the researchers were still struggling to make sense of them.

Kunbarrasaurus also has very different nasal passages to those found in the larger, more developed ankylosaurs of North America and Asia, Dr Salisbury added.

Instead of the looping "crazy straw" nasal passages, Kunbarrasaurus has smaller loops, which are thought to be part of the animal's cooling system to compensate for the overheating risk from its heavy armour.

Less armour makes skull easier to study

Loading...

This specimen also has slightly less armour covering its body, and lacks the distinctive and familiar club-like tail.

The fact that Kunbarrasaurus has less dense armour, particularly on its head, has actually made it easier to study the bones of the skull (seen in the video above), according to lead author and PhD candidate Lucy Leahey, from the University of Queensland.

"It's one of only four skulls in the world where you can see the bones of the skull — in a lot of the stuff from North America and Asia, the dermal armour fuses to the skull," Ms Leahey said.

Ms Leahey said the sheep-sized Kunbarrasaurus is also much smaller than its several-tonne northern hemisphere relatives and may represent a more primitive lineage.

"Stegosaurus and ankylosaurus share a common ancestor and most of the examples of ankylosaurs are quite advanced," Ms Leahey said.

"Kunbarrasaurus is quite primitive so it's closer towards that common ancestor than to the higher, more advanced forms."

The name Kunbarrasaurus is derived from 'Kunbarra' — the word for 'shield' in the Mayi language of the local Wunumara people.

The species name 'ieversi' honours Mr Ian Ivers, the property manager who originally found the fossil.