A new species of armoured dinosaur has been discovered with a skull and snout heavily covered with spikes and a large bony club at the end of its tail.
Dubbed the Akainacephalus johnsoni, the herbivorous dinosaur, which has never before been described in scientific literature, was discovered by paleontologists in southern Utah.
"This is a really remarkable species," Jelle Wiersma, a doctoral candidate in geosciences at Australia’s James Cook University and a co-author of the study announcing the discovery, told CTVNews.ca. "The preservation of the fossils is remarkable."
Wiersma described the Akainacephalus as a four-legged, medium-sized dinosaur that was roughly 5 metres long and 1.5 metres tall. While it would have been prey for carnivorous dinosaurs such as tyrannosaurs, its tank-like shape and bony tail club would have allowed it to deal "pretty significant blows" to predators.
"It seems like they were well able to defend themselves," Wiersma said in a telephone interview from Australia. "The best way to get to them would have been to flip them over."
The dinosaur’s name has Greek origins: "Akaina" means "thorn" or spike," while "cephalus" means "head." 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.
"I never thought that I would have the opportunity to actually work on fossils that could be important for paleontologists," Johnson said in a news release, describing his work as "a dream second career."
Armoured dinosaurs originated in Asia between 125 million and 100 million years ago and did not appear in North American fossil records until nearly 77 million years ago. The Akainacephalus roamed the earth during the Late Creataceous Period, nearly 76 million years ago.
Ankylosaurids are quite rare in the fossil records, according to Wiersma.
The uniquely pointy and more pronounced shape of the armour covering the Akainacephalus has led researchers to believe that while the species was discovered in North America, its closest relatives come from Asia. North American ankylosaurids have flatter armour on their bodies.
Wiersma said that the Akainacephalus likely crossed the Beringian land bridge that connected Asia with North America when sea levels were low enough to expose the crossing.
The discovery was made at the upper Campanian Kaiparowits Formation in the Grand Staircase-Escalante National Monument in Kane County, Utah, in 2004.
Wiersma said that the discovery site was part of a river system that at some point breached its bank. Animals either died on the floodplain or drowned.
While it is not uncommon for new species of dinosaurs to be unearthed, a lot of time elapses before researchers can announce their discovery to the public.
Fossils must be delicately cleaned and repaired before researchers can even begin studying them, and discoveries can only be broadcast to the public once a peer-reviewed academic journal publishes a study on the finding.
"For every hour we spend in the field, it takes hundreds of thousands of hours to prepare the specimens so they can be accessible for researchers," Wiersma said.
He added that researchers still have many questions about the Akainacephalus, including what their growth rates were and whether there were differences between males and females.
But before they can answer them, they’ll need to unearth more fossils.
"The search is ongoing," Wiersma said.
