Along with a complete skull, the fossil also includes the distinctive tail club, large parts of its spinal vertebral column and parts of its body armour, including two neck rings and spiked armour plates, the museum said in a statement. A new analysis indicates that the newfound, 76-million-year-old ankylosaur species, dubbed Akainacephalus johnsoni, likely had Asian ancestors that migrated to North America when sea levels between the continents were low, researchers said in a new study, published online today (July 19) in the journal PeerJ.
The fossil unveiled on 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. The latter half of its name, johnsoni, honours Randy Johnson, a museum volunteer who helped to prepare its skull.
Jelle Wiersma, who has been a PhD candidate at James Cook University in Townsville, was the lead author of a new article that described and named the herbivore.
The armoured dinosaurs, known as ankylosaurids, were expected to look like other North American ankylosaurids, but instead resembled an Asian species - which had protective spiky armour covering the skull and snout.
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. Considered a medium-size ankylosaur, A. johnsoni was closely related to another ankylosaur found in the U.S. Southwest, namely the Nodocephalosaurus kirtlandensis of New Mexico.
Although for many years in the South-West of the US there were a lot of remains ankylosaurids, a recent fossil from Utah was the most complete skeleton of this dinosaur in America.
Measuring between 13 and 16 feet in length and 3.5 feet tall, Akainacephalus jonhnsoni is slightly smaller than its more well known cousin, Ankylosaurus. Now their remains are found in different parts of the Earth.
Akainacephalus johnsoni provides valuable new insights suggesting multiple ankylosaurid emigration events from Asia to Laramidia during the Late Cretaceous.
Nothing like what the scientists did not find, so took the dinosaur to a new kind.
"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. It wasn't until about 77 million years ago that they started showing up in North America, according to the fossil record.
This caused isolation along western and eastern portions of the North American continent during the Late Cretaceous epoch, between 95-70 million years ago.
"It is extremely fascinating and important for the science of paleontology that we can read so much information from the fossil record, allowing us to better understand extinct organisms and the ecosystems they were a part of", Wiersma said.