The genus name essentially means "spike-head", but the name of the species is in honor of museum volunteer Randy Johnson, a retired chemist who helped prepare the skull.
"I never thought I would have the opportunity to actually work on fossils that might be important to paleontologists," Johnson said in a statement. "Now that I'm a museum expert, I get the opportunity to work on a wide variety of fossils and consult with top paleontologists – it's like a dream career, I could not believe it when they told me they were it is a unique honor to name the Ankylosaurian after me. "
Akainacephalus walked on four legs directly under his body and was considered medium-sized, measuring between 1
The fossil consists of a complete skull, most of the spine, front and hind limbs, bony body armor rings and spiky armor plates, and a full tail stick. It is the most complete skeleton of this type of armored dinosaur ever found in the southwestern United States.
It was found in the Kaiparowits formation of the monument where rocks and mud were deposited by rivers and streams.
The fossil was discovered in 2008 during a paleontological expedition together with a duck-billed dinosaur, a new turtle species and a relative of alligators. The bones took almost four years to prepare.
A study on the find was made on Thursday in connection with the announcement of
Ankylosaurids were herbivores that were known for their intimidating bone bats and body armor, and their fossils were found earlier in North America. But this well-preserved fossil showed a surprising detail.
The Ankylosaurid fossils associated with North America exhibited smooth bone armor on their skulls. This had pronounced spiky, bony armor that covered the skull and muzzle, closely related to Asian Ankylosaurids that lived 125 million years ago.
"A reasonable hypothesis would be that Ankylosaurids from Utah are related to those in other parts of West-North America, so we were surprised that Akainacephalus was so closely related to species from Asia," said Randall Irmis, co-author of the study and Curator of Paleontology at the Natural History Museum of Utah, said in a statement.
The fossil helped the researchers to establish that at least two immigration events occurred during the Late Cretaceous, resulting in two groups of ankylosaurid Dinosaurs led.
When the sea level reached some of the highest in our planet's history, the Western Interior Seaway split the North American continent in two. The western and eastern parts of the continent were isolated. In the west was Laramidia, and in the east was Appalachia. These would come together again to form North America, which would cause the two essentially lost continents to be lost.
Akainacephalus would have roamed the southern part of Laramidia, which once extended from the Arctic Circle to the Gulf of Mexico.
But the sea level dropped several times, allowing dinosaurs and animals to cross the Beringian land bridge between Asia and western North America. This also explains that the Asian Ankylosaurid dinosaurs are moving to North America.
"It is always exciting to call a new fossil taxon, but it is equally exciting that this taxon also gives additional insights into the larger picture of his life, such as his diet or aspects of his behavior and the environment in which he lived "Jelle Wiersma, lead author and graduate student in the Department of Earth Sciences at James Cook University in Australia, said in a statement.
Almost every dinosaur species discovered in the Grand Staircase-Escalante National Monument is new to science, including Akainacephalus. This part of Laramidia has been incredibly diverse in plant and animal life between 75 million and 80 million years. Possible reasons for the diversity of the area are the sea level, climatic differences across the width or barriers such as mountains and rivers.
"It is extremely fascinating and important for the paleontology science to be able to read so much information from the fossil record that allows us to better understand extinct organisms and the ecosystems in which they were involved," Wiersma said , "An important long-term goal of our work in southern Utah is to try to understand why species in GSENM differ from relatives of the same geological age that occur in other parts of Laramidia."