Scientists have uncovered a duck-billed dinosaur that could prove to be the missing link in the evolution of this particular branch of dinosaurs. Duck-billed dinosaurs are among the most famous dinosaurs, possibly due to the fact that some of them feature an uncanny resemblance to modern-day ducks.
The discovery and analysis was made by researchers at Montana State University, who have concluded that new fossils for a dinosaur called Probrachylophosaurus belong to the Brachylophosaurini, a branc of the “duck-billed” dinosaurs. The Probrachylophosaurus roamed North America about 79.8 to 79.5 million years ago.
This date is the key because the Acristavus gagslarsoni preceded the duck-billed dinosaurs, living some 81 to 80 million years ago. The Brachylophosaurus Canadensi had a paddle-shaped nasal crest and lived about 77.8 million years ago.
It appears that the Probrachylophosaurus may been the link between these two dinosaur species, featuring many traits in common with both of them. This dinosaur could be the stepping stone between non-crested and crested dinosaurs.
The fossils of the Probrachylophosaurus were excavated in Montana, at the Judith River Formation. The vast majority of the fossils discovered in the river formation date from the upper Cretaceous, about 75 to 80 million years ago.
After finding the fossils and comparing them to both the Acristavus and Brachylophosaurus, researchers realized that they may have stumbled across the long sought missing link between the two. The crest seen on the Probrachylophosaurus is quite moderate in size and represents a gradual evolution from non-crested to crested.
The research was conducted by MSU adjunct professor Elizabeth Freedman Fowler, and her mentor Jack Horner, a well-regarded paleontologist who is also based at MSU. Horner is the Montana University System Regents Professor and also the paleontology curator at the Museum of the Rockies.
Freedman Fowler completed her PhD in 2015 at Montana State, and serves as the curator of paleontology at the Great Plains Dinosaur Museum in Malta.
The discovery of the fossil, its dating, and its place in the evolutionary chain of the duck-billed dinosaurs provides a key insight into this family of dinosaurs. The study itself was published in Plos One.