Unique Armored Dinosaur Discovered In Utah

The fossil reveals new details about the diversity and evolution of ankylosaurid dinosaurs

In 2008, researchers found the fossil of a remarkable armored dinosaur in southern Utah. The North American Late Cretaceous ankylosaurid dinosaur was covered in a smooth bony armor but it seems to be more closely related to ankylosaurids found in Asia than to ones that lived in northern America.

The new species of ankylosaurid dinosaur lived 76 million years ago during the Late Cretaceous Period and roamed the lost continent of Laramidia. Although many ankylosaurids dinosaur fossils have been found over the years in the southwestern US, the recent fossil offers the most complete skeleton of an ankylosaurid in the region. The fossil includes a complete skull, vertebrae and limb bones, as well as a perfectly preserved bony body armor.

The most interesting thing about this dinosaur is its spiky bony armor covering the skull and snout. These defining features make it look surprisingly similar to Asian ankylosaurids that originated in Asia between 125 to 100 million years ago.

"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.” Co-author of the study Randall Irmis said in a statement.

A new analysis indicates that the diversity and evolution of armored dinosaurs in the region was the result of brief intervals of lowered sea level that allowed Asian ankylosaurid dinosaurs to immigrate to North America several times during the Late Cretaceous. Lower sea levels exposed the Beringian land bridge and allowed dinosaurs and other animals to move between Asia and North America, which led to the presence of two separate groups of ankylosaurid dinosaurs.

“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," said lead author Jelle Wiersma.

“…Akainacephalus johnsoni; not only is this the first described and named Late Cretaceous ankylosaurid dinosaur from Utah, but this unique animal also strengthens the idea the evidence that distinct northern and southern provincialism existed during the late Campanian stage in Laramidia, because to date, we don't see this type of ankylosaurid dinosaurs in the fossil record of northern Laramidia.”

Akainacephalus johnsoni has been assigned to a new genus. The genus name comes from the Greek words akaina, which means 'thorn' or 'spike', and cephalus, meaning 'head.' The other part of the name honors Randy Johnson, a dedicated museum volunteer who skillfully reconstructed its skull.

Let's block ads! (Why?)