Published: Sat, July 21, 2018
Science | By

New spiky-skulled dinosaur lived on a lost continent

New spiky-skulled dinosaur lived on a lost continent

The "johnsoni" pays homage to Randy Johnson, a retired chemist and volunteer at Utah's Natural History Museum, who spent thousands of hours preparing the fossils for study.

"Someone once told me that Akainacephalus, and ankylosaurs in general, were quite ugly and had a face only a mother could love".

A new species of dinosaur has been discovered with the help of a North Queensland scientist.

Working in this high desert terrain, palaeontologists from the Natural History Museum of Utah and the University of Utah managed to pull out a number of bones, including an immaculately preserved complete skull, bony armour (including neck rings and spiked plates), several vertebrae, a forelimb, various hindlimb bones, and almost complete tail with the iconic ankylosaur club still attached. Like other ankylosaurid dinos, this creature was built for defence; it featured formidable armour from head to tail, including bony plates called osteoderms.

A life reconstruction of the newly discovered Cretaceous Period armored dinosaur Akainacephalus johnsoni, which lived 76 million years ago in Utah, surrounded by the crocodilian Denazinosuchus is seen in this image provided July 19, 2018.

The museum's palaeontology curator, Randall Irmis, who also advised Mr Wiersma and was the co-author of the study, said the reconstructed skeleton would excite many visitors. But this well-preserved fossil revealed a surprising detail.

The species is believes to have originated in Asia up to 125 million years ago, but did not appear in the North American fossil record until 77 million years ago.

Similar to the Ankylosaurus, Akainacephalus had bony armor covering its entire body and had spikes and horns on its skull.

"The geographic distribution of Late Cretaceous ankylosaurids throughout the Western Interior was the result of several geologically brief intervals of lowered sea level that allowed Asian ankylosaurid dinosaurs to immigrate to North America several times during the Late Cretaceous, resulting in the presence of two separate groups of ankylosaurid dinosaurs", Wiersma said. Eventually, the sea shrank and the two parts combined to form what is now known as North America.

The unique shape and arrangement of its head and snout armor may be its most intriguing trait, the researchers said, giving clues about the Asian ancestry of some of the ankylosaurs that roamed western North America near the end of the dinosaur era. The western and eastern portions of the continent were isolated.

"We want to bring this lost ecosystem to life for visitors, and Akainacephalus is one type of animal that lived in this environment - a particularly compelling one."
North American ankylosaurids have flatter armour on their bodies.

The fossil unveiled Thursday at the Natural History Museum of Utah was first discovered in 2008 in the Grand Staircase-Escalante National Monument, a rich dinosaur repository in southern Utah.

"Ankylosaurid dinosaurs evolved initially in Asia and migrated over to North America during low sea levels and then the Bering Strait becomes exposed", he said.

Besides the revelation of a new dinosaur, there's more in store he said. "A major long-term goal of our work in southern Utah is to try and understand why the species in GSENM differ from relatives of the same geologic age found in other parts of Laramidia".

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