A missing link in evolution was found when a discovery of a new species of dinosaur fossil was made at north central Montana.

A dinosaur fossil around 79 million years old was unearthed by a team from Montana State University. The fossil turned out to be that of a duck-billed dinosaur that was most likely the ancestor of the Maiasaura, the state's dinosaur.

"When everything was cleaned, it revealed this little crest [on its head] like nothing we'd ever seen," said Elizabeth Freedman Fowler, who was also a curator of paleontology at the Great Plains Dinosaur Museum in Malta.

The fossil was named Probrachylophosaurus bergei which roughly means early short-crested lizard. Its characteristics fit in well between the Acristavus gagslarsoni, a dinosaur that thrived about 80 million years ago with no crest on its head, and the Brachylophosaurus canadensis from at least 77 million years ago that had a big, flat crest on its nose.

It also became known as the Super Duck because of its size, being one of the larger members of the duck-billed dinosaur family.

Scientists noted that the crest on the dinosaurs may have the same purposes as those of modern birds. Some birds have crests made of feathers or keratin which then grow in size and shape as they mature. They are mainly meant to attract mates.

"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," Fowler said.

Fowler added that because the size of the crest on the dinosaurs appeared to grow larger among different members of its family over time, evolution may have seen this trait as a valuable one and retained it over different species.

It is thought that both male and female duck-billed dinosaurs may have had crests but may have sported them in different sizes, patterns and colors.

The fossils were first found in Rudyard plains back in 1981, but were only excavated last 2007 to 2008 by teams from Bozeman's Museum of Rockies. Fowler and her study's co-author, Jack Horner helped to study it.

Based on its appearance, the front of the dinosaur's nose was broken, though it appeared to be an already healed bite from a different creature. Also, judging by predator teeth scattered within its vicinity, it may have either been hunted down or scavenged by larger carnivores.

Fowler was grateful that the bones were found in good condition despite the difficulty in finding and piecing them together.

"We were very lucky that was preserved," Fowler said.