BOZEMAN: A previously undiscovered dinosaur species, first uncovered and documented by an adjunct professor at Montana State University, showcases an evolutionary transition from an earlier duckbilled species to that group’s descendants, according to a paper published today in the journal PLOS ONE.
The paper was written by that professor, Elizabeth Freedman Fowler, and her mentor, MSU paleontologist Jack Horner, Montana University System Regents Professor and curator of paleontology at MSU’s Museum of the Rockies. Their findings highlight how the new species of duckbilled dinosaur neatly fills a gap that had existed between an ancestral form with no crest and a descendant with a larger crest, providing key insight into the evolution of elaborate display structures in these gigantic extinct herbivores.
“It is really gratifying to see Dr. Freedman Fowler’s work, which is essentially her dissertation, published in PLOS ONE,” Horner said. “It is confirmation that she is an excellent paleontologist, helping further cement MSU’s reputation for offering graduate students a chance to be part of something extraordinary.”
In their paper, Freedman Fowler and Horner named the dinosaur Probrachylophosaurus bergei and suggest it is a previously missing link between a preceding species, Acristavus, which lived about 81 million years ago, and later form Brachylophosaurus, which lived about 77.5 million years ago.
“The crest of Probrachylophosaurus is small and triangular, and would have only poked up a little bit on the top of the head, above the eyes,” said Freedman Fowler, who received her doctorate in paleontology from MSU’s Earth Sciences Department in 2015. She also serves as curator of paleontology at the Great Plains Dinosaur Museum in Malta.
The other bones in its skull are very similar to those of Acristavus and Brachylophosaurus, Freedman Fowler said. However, Acristavus does not have a crest; the top of its skull is flat, while Brachylophosaurus has a large flat paddle-shaped crest that completely covers the back of the top of its skull.