Sure, bison roamed the plains here, but what about the school bus-sized sea lizards with angry eyebrows?

Nov. 15—WALHALLA, N.D. — North Dakota high schools looking to replace outdated school nicknames are in luck. Thanks to science, the following mascots are now as representative of our state as bison, buffaloes, roughriders or vikings.

How do these sound to you?

The Fighting Jǫrmungandrs?

The Walhallaensis Warriors?

The Mighty Mosasaurs?

Okay, maybe they need a little work.

But the fact is any of those names would work after the American Natural History Museum recently released the name of a giant sea lizard "with angry eyebrows" who once swam here.

The new species: Jǫrmungandr walhallaensis, was named after Jǫrmungandr, a sea serpent in Norse mythology, and the small North Dakota city, Walhalla, near where the fossil was found in 2015.

"If you put flippers on a Komodo dragon and made it really big, that's basically what it would have looked like," said the study's lead author Amelia Zietlow, a doctoral student in comparative biology at the American Museum of Natural History's Richard Gilder Graduate School.

The fossil on which the study is based is an impressive specimen of a predatory marine lizard called a mosasaur and included a nearly complete skull, jaws and cervical spine, as well as a number of vertebrae. After extensive analysis and surface scanning of the fossil material, Zietlow and colleagues found that this animal is a new species with a mosaic of features seen in two iconic mosasaurs: Clidastes, a smaller and more primitive form of mosasaur, and Mosasaurus, a larger form that grew to be nearly 50 feet long and lived alongside Tyrannosaurus rex.

Jǫrmungandr walhallaensis is estimated to be about 24 feet long (that's almost as long as a school bus) and, the new study suggests, would have lived about 80 million years ago, predating Mosasaurus. In addition to flippers and a stumpy, shark-like tail, Jǫrmungandr had a bony ridge on its skull that would have given it the appearance of having "angry eyebrows."

Mosausaurs lived between 100 and 66 million years, becoming extinct at the same time as non-avian dinosaurs in the aftermath of the asteroid strike. Many questions about this marine reptile group remain, including how many times they evolved flippers and became fully aquatic and whether they are more closely related to monitor lizards or snakes.

Senior Paleontologist for the North Dakota Geological Survey Clint Boyd was a co-author of the study. In a 2017 interview, he said the Pembina Gorge, where the fossils were found, is a place unlike any other in the state as more and more people are discovering the fascinating fossil digs going on there, making discoveries of giant sea creatures that swam the inland sea that covered this area millions of years ago.

"Think of us sitting in the shallow part of the Gulf of Mexico, really warm and shallow, only a few tens of feet deep," said Boyd, "Lots of life and fish and reptiles and creatures that were wandering around at the time."

He said this fossil is coming from a geologic time in the United States that we don't really understand.

"The more we can fill in the geographic and temporal timeline, the better we can understand these creatures," Boyd said.