Malta, Montana – A paper published Wednesday in the journal PLOS ONE revealed the discovery of a duck-like dinosaur fossil that lived about 79 million years ago and grew up to 30 feet. Because of the small triangular bony crest at the top of its skull, this dinosaur is part of an evolutionary transition, as it perfectly fills the gap between its descendants and a previous duckbilled species.
Researchers from the Museum of the Rockies found the fossil, which they called Probrachylophosaurus bergei, while excavating at Montana’s Judith River Formation. They also found less-complete rests of another Probrachylophosaurus.
P. bergei constitutes a transitional species between the non-crested Acristavus, a duck-billed dinosaur which lived about 81 million years ago, and the large-crested Brachylophosaurus from 78 million years ago. The description was documented by Elizabeth Freedman Fowler, an adjunct professor at Montana State University and curator of paleontology at the Great Plains Dinosaur Museum in Malta.
“It is a perfect example of evolution within a single lineage of dinosaurs over millions of years,” claimed Fowler. She wrote in the paper that the discovery provides the key to understanding the evolution of elaborate display structures in these huge herbivores.
Although the Probrachylophosaurus is not the largest of its kind, Fowler explained that she gave it the nickname “Superduck” because it was pretty big for a duck-billed dinosaur. The P. bergei was about 14 years old, was a member of a group known for having beaks resembling a duck’s bill, a common characteristic in the latter part of the Cretaceous Period.
Fowler believes that the crests of dinosaurs were visual signals they used to distinguish members of their own species from other animals and also to tell if they were mature or not. She suggested that this could support the idea that most dinosaurs were social animals, not very different from most modern birds.
In 2007 the paleontologist led a crew from the Museum of the Rockies in an excavation of a bed of earth near the town of Rudyard in north central Montana, where they found fossils of duckbilled dinosaurs.
Freedman Fowler affirmed that the Late Cretaceous of western North America was the only place on Earth where such profound paleobiological studies on dinosaurs could take place since the location combines the precise dating of rocks coupled with a remarkably high fossil record that has been collected over the years.