species of prehistoric sea creature that lived about 70 million years ago in the inland sea that flowed
east of the Rocky Mountains.
The new species of elasmosaur is detailed in an article published Thursday in the Journal of
Vertebrate Paleontology. Most elasmosaurs, a type of marine reptile, had necks that could stretch
18 feet, but the fossil discovered in the Charles M. Russell National Wildlife Refuge is distinct for its
much shorter neck — about 7½ feet.
“This group is famous for having ridiculously long necks, I mean necks that have as many as 76
vertebrae,” said Patrick Druckenmiller, co-author of the article and a paleontologist with the
University of Alaska Museum of the North. “What absolutely shocked us when we dug it out — it
only had somewhere around 40 vertebrae.”
The smaller sea creature lived around the same time and in the same area as the larger ones, which
is evidence contradicting the belief that elasmosaurs did not evolve over millions of years to have
longer necks, co-author Danielle Serratos said.
Elasmosaurs were carnivorous creatures with small heads and paddle-like limbs that could grow as
long as 30 feet. Their fossils have been discovered across the world, and the one discovered in
northeastern Montana was well-preserved and nearly complete.
The refuge adjacent to the Missouri River is popular with hunters for its big game and remote
David Bradt, a ranch manager from Florence, Montana, said he was hunting elk unsuccessfully in
November 2010 when he walked into a canyon to splash some water on his face.
In the creek, the water ran over what he thought was petrified wood sticking out of a rock. He pulled
back the brush, saw vertebrae and knew it was fossilized bones.
He thought it was a dinosaur and was floored when he learned it was a sea creature.
“It’s about the size of a cow, and I’m thinking it’s a triceratops,” he said. “I didn’t know there was an
Bradt took photographs and reported the find to the US Fish and Wildlife Service and the Museum of
the Rockies in Bozeman.
It took three days to excavate the fossil, but much longer to clean and study it before the
determination could be made that it was a new species, Druckenmiller said.
He said the inland sea that stretched the width of Montana to Minnesota and from Canada to the
Gulf of Mexico was teeming with marine reptiles, but relatively few of their fossils have been
“It’s a total bias — just more people out there are interested in land-living dinosaurs than marine
reptiles,” he said. “There would be a lot more known if more people were studying them.”