Meet NHMU's Newest Dinosaur: Akainacephalus johnsoni

Akainacephalus johnsoni
Image © Andrey Atuchin/DMNS

 

Meet Akainacephalus johnsoni

A brand new genus and species of ankylosaurid dinosaur has been unearthed in Grand Staircase-Escalante National Monument (GSENM), in southern Utah and is now on display in our Past Worlds Exhibition.

The animal lived 76 million years ago during the Late Cretaceous Period and reveals exciting new insight into  the diversity and evolution of this group of armored dinosaurs.

The dinosaur was medium-sized, standing at 3 feet 6 inches tall and strtching about 15 feet long. It inhabited present-day southern Utah, which during the Late Cretaceous Period was part of the southern portion of Laramidia, an island continent that stretched from the Arctic Circle to the Gulf of Mexico.


Akainacephalus provides new insight

Akainacephalus johnsoni
Photo © Andrey Atuchin/DMNS

Ankylosaurids are a group of four-legged herbivorous, armored dinosaurs with imposing, bony tail clubs. Though ankylosaurids originated in Asia between 125 - 100 million years ago, they do not appear in the western North American fossil record until about 77 million years ago. The new species Akainacephalus offers the most complete skeleton of an ankylosaurid dinosaur found in the southwestern United States. It includes a skull, much of the vertebral column, including a complete tail club, several fore and hind limbs elemnts, and bony body armor that includes two neck rings and spiked armor plates.

The unique arrangement of bony armor in the shape of small cones and pyramids covering the snout and head is the key research finding indicating that Akainacephalus is closely related to Asian ankylosaurids such as Saichania and Tarchia than to other Late Cretaceous North American ankylosaurids, including Ankylosaurus and Euoplocephalus.

These findings are part of a study funded in large part by the Bureau of Land Management, the Geological Society of America, and a University of Utah Department of Geology & Geophysics Graduate Student Grant. The project was led by University of Utah M.Sc. student Jelle Wiersma, now a Ph.D. student in the Department of Geosciences at James Cook University, Queensland, Australia. Wiersma was advised by co-author Dr. Randall Irmis, Chief Curator and Curator of Paleontology at NHMU, and Associate Professor in the Department of Geology and Geophysics, at the University of Utah.


Akainacephalus johnsoni Facts:

Name: Akainacephalus johnsoni derives its name from the Greek words akaina, which means 'thorn' or 'spike,' and cephalus, meaning 'head.' The species epithe johnsoni honors Randy Johnson, a dedicated Museum volunteer who skillfully prepared its skull.

Size: Akainacephalus was between 13 - 16 feet long and stood about 3 feet 6 inches tall.

Relationships: Akainacephalus belongs to a group of herbivorous, armored dinosaurs called ankylosaurids that lived in Asia and western North America during the Late Cretaceous Period (100 - 66 million years ago).

Anatomy: Akainacephalus walked on four legs, which were positioned directly underneath its body. It was covered in bony armor from head to tail, with various sized and shaped bony plates, called osteoderms, which are thought to provide protection. Akainacephalus is characterized by its elaborate covering of spikes and horns on the skull, as well as a large, bony club at the end of its tail.

Age and Geography: Akainacephalus lived during the upper Campanian stage of the Late Cretaceous Period, which spanned from approximately 84 million to 72 million years ago. This animal lived about 76 million years ago.

Discovery: Akainacephalus was first discovered by Scott Richardson, a BLM employee who also discovered Lythronax and Kosmoceratops, all in the same region of Grand Staircase-Escalante National Monument.

Preparation: It took nearly four years to fully prepare all of the bones of Akainacephalus. Preparation of the skull was done by Museum volunteer Randy Johnson, who is honored in the name, Akainacephalus johnsoni.



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