Fossil Discovered By Elk Hunter Belongs To New Species Of Plesiosaur With Shorter Neck
In November 2010, ranch manager David Bradt was hunting elk in northeast Montana when he found what first appeared to be a petrified wood sticking out of a rock. He eventually discovered that it was a vertebrae of fossilized bones.
That fossil helped researchers discover a new species of prehistoric marine reptile that swam in the inland sea flowing east of the Rocky Mountains about 70 million years ago.
Scientists named the new species Nakonanectes bradti, which stands for Nakona, or Assiniboine, the people of northeastern Montana, and Bradt who first discovered the specimen while hunting elk.
Long-Necked Sea Creature
The marine animal belonged to a group of long-necked plesiosaurs called elasmosaur, which are characterized by small heads and paddle-like limbs and can grow up to 30 feet long. The carnivorous reptiles are a type of prehistoric marine creature that are known for their long neck that stretches 18 feet long.
The fossil that Bradt discovered in the Charles M. Russell National Wildlife Refuge called MOR 3072 is distinct in that it belonged to a creature that has a shorter neck measuring just about 7.5 feet.
Paleontologist Patrick Druckenmiller, from the University of Alaska Museum of the North, who coauthored the study describing the fossilized remains of the new species, said that this group of prehistoric animals is known for their long necks, which contain as many as 76 vertebrae.
"What absolutely shocked us when we dug it out — it only had somewhere around 40 vertebrae," Druckenmiller said.
The creature lived in the same area and at the same time as its larger relatives, which contradicts the idea that elasmosaurs did not evolve over a period spanning millions of years to have their longer necks.
Fossils Initially Thought To Be Of Triceratops
Fossils of these creatures have been found across the world, but the one that was discovered in Montana was nearly complete and was well-preserved.
When Bradt found the fossils, he initially thought these belonged to a triceratops. He was surprised to learn it was a sea creature because he did not know there used to be an ocean there.
Bradt took photos and reported his find to the Museum of the Rockies in Bozeman and the U.S. Fish and Wildlife Service. It took three days before the fossil was excavated.
Millions of years ago, dinosaurs such as Tyrannosaurus rex, Thescelosaurus, Triceratops, and Pachycephalosaurus inhabited the land and sea in the area. Researchers said that the inland sea was also teeming with marine creatures, but relatively a few of these fossils have so far been excavated.
"MOR 3072 is one of the smallest adult elasmosaurids ever recovered (5.1-5.6 m) and exhibits a reduced neck length compared with other North American elasmosaurids, resulting from a reduction in both centrum length and number of cervical vertebrae (39-42 were originally present)," researchers wrote in their study, which was published in the Journal of Vertebrate Paleontology on Thursday, April 13.
"These features are convergent with the Southern Hemisphere clade of short-necked Maastrichtian elasmosaurids, Aristonectinae, and demonstrate multiple origins of short-necked body proportions from longer-necked ancestors within Elasmosauridae."