July 20, 2018 - 15:13 AMT
PanARMENIAN.Net - A fossil of a new species of armoured dinosaur has been discovered in Utah, changing how scientists believe the animals evolved, SkyNews reports.
It took almost four years to prepare and analyse the medium-sized dinosaur's skeleton, which is 13-16ft long (4-5m) and about 42 inches (1.5m) tall at the hip, and one of the most complete ever discovered in this region of the US.
Armoured dinosaurs, or ankylosauridae, existed exclusively in the northern hemisphere before they became extinct 66 million years ago.
Fossils have been found in North America, East Asia and Europe, and the three regions have different forms of armour to differentiate them.
But the new species, Akainacephalus johnsoni, breaks the rules for North American ankylosaurids.
Instead of the distinctive smooth armour on the skull shown on other North American fossils, the new species has pointed bones protruding in ridges up to its snout - similar to Asian ankylosaurid fossils.
Dr Randall Irmis, co-author of the study, said: "A reasonable hypothesis would be that ankylosaurids from Utah are related to those found elsewhere in western North America, so we were really surprised to discover that Akainacephalus was so closely related to species from Asia."
"It is always exciting to name a new fossil taxon, but it is equally exciting if that taxon also provides additional insights into the bigger picture of its life, such as its diet or aspects of its behaviour, and the environment it lived in," said lead author Jelle Wiersma.
The species' name was given in honour of Randy Johnson, a dedicated museum volunteer who spent hundreds of hours preparing the fossil's skull by separating it from surrounding rock and debris.
He said it was a "once in a lifetime honour" to have the dinosaur named after him.
"I'm a retired chemist, but I've always been interested in most of the science disciplines," Johnson said.
"I never thought that I would have the opportunity to actually work on fossils that could be important for palaeontologists.