A fossil braincase and partial skull roof from Carnegie Museum of Natural History has been reassessed and reclassified, giving rise to a new genus and species of dicraeosaurid sauropod dinosaur: Athenar bermani.
Athenar bermani lived in what is now Utah, the United States, during the Late Jurassic, 151 to 150 million years ago.
The dinosaur's remains, designated as the Carnegie Museum (CM) specimen 26552, were originally collected in 1913 in rocks belonging to the Morrison Formation in Carnegie Quarry at Dinosaur National Monument.
Until now, the specimen was assigned to a genus of sauropod dinosaurs called Diplodocus.
"Carnegie Museum of Natural History houses some of the most important specimens for our understanding of diplodocoid sauropod cranial anatomy," said Dr. John Whitlock, a researcher at Mount Aloysius College and Carnegie Museum of Natural History.
"One specimen, CM 26552, is often overlooked in favor of more complete skulls, but bears an outsized historical importance as this specimen formed the basis for the modern description of braincase anatomy for Diplodocus as a genus."
"In light of several decades of new discoveries since the original description in 1978, we re-evaluate the anatomy and taxonomic relationships of this specimen."
The new analysis shows that the features of CM 26552 align better with a different group of sauropods: the Dicraeosauridae.
"CM 26552 exhibits a mosaic of traits that enable it to be confidently differentiated from the other known North American dicraeosaurid species," the paleontologists said.
"Considering CM 26552 as a new dicraeosaurid species enhances the knowledge of the diversity of this family in the Morrison Formation and in North America more generally, expanding the historically underestimated sauropod diversity of the unit," the researchers said.