5-Ton 'Superduck' Dino Featured Flashy Crest

"Superduck," a newly unearthed big dinosaur from Montana, featured a flashy head crest that suggests it was a missing link between other known duck-billed dino species, according to a new study.

The distinctive crest of the new dinosaur, Probrachylophosaurus bergei, links it to a related earlier dino with no crest and another, later species that had a large one.

Superduck's "crest would have only poked up a little bit on the top of the head, above the eyes," said Elizabeth Freedman Fowler of the Museum of the Rockies and Montana State University.

"We cut open one of its leg bones, the tibia, and counted the growth rings," she continued. "Superduck was 14 years old when it died, and it was close to full size, but it would have grown a bit larger if it had lived longer. It was about 29 feet long and would have weighed about 5 tons."

She and co-author John Horner analyzed Superduck's remains, which were unearthed at the Judith River Formation of north-central Montana. The dinosaur was dated to approximately 79.5 million years ago.

Its fossils were found to be similar to those of another plant-eating dinosaur, Brachylophosaurus, which lived around 78 million years ago, and Arcristavus, which lived 81 million years ago.

Arcristavus had no head crest, but Brachylophosaurus had a large, flat paddle-shaped crest that completely covered the back of the top of its skull. The three dinosaurs are therefore believed to be related, with Superduck being an intermediary.

"It is a perfect example of evolution within a single lineage of dinosaurs over millions of years," Freedman Fowler explained.

She and Horner said that such crests were either too small, or too large and fragile, for use in head fights. Instead, they think that the head ornamentation of both males and females would have been used as visual signals so that the dinos could recognize members of their own species and also tell whether or not the animal was mature.

The study, published in PLOS ONE, adds to the growing body of evidence that most dinosaurs, like today's birds, were very social animals.

"On a crowded floodplain, you want to make sure you stay with the right (dinosaur) herd," Freedman Fowler explained. "The crests may have also helped them attract mates. Just like with modern birds that have big colorful feathers and dances to show how strong and healthy they are, dinosaur crests aren't essential for the animal's life, so by spending energy growing a big, flashy crest, the animal is advertising that it's doing really well in life, and has really good genes."

There was a risk to such head bling, though. The dinosaur's warm environment had a meandering river and was rich in vegetation, so it was also home to horned dinosaurs, such as Wediceratops, newly unearthed Medusaceratops, and soon-to-be-renamed Gryposaurus.

Read more at Discovery News