Revelatory Fossil Reveals Duck-Billed Dinosaur had a Rooster-like Crest Atop its Head

A species of Cretaceous-era duck-billed dinosaur that was previously thought to be rather plain in appearance turns out to have had a fleshy flap of skin on the top of its head, as evidenced by an exquisitely mummified fossil uncovered in Canada.

The wobble of flesh atop the head of Edmontosauraus regalis is believed to be akin in structure to that of a rooster's cockscomb, the prehistoric-looking fan of flesh atop its head.

Although duck-billed dinosaur species are well studied - having been the most common dinosaur in North America between 75 million and 65 million years ago - it was never expected that a duck-billed dinosaur would have had a fleshy adornment atop its head.

"Until now, there has been no evidence for bizarre soft-tissue display structures among dinosaurs; these findings dramatically alter our perception of the appearance and behavior of this well-known dinosaur and allow us to comment on the evolution of head crests in this group," said Phil Bell from Australia's University of New England. "It also raises the thought-provoking possibility of similar crests among other dinosaurs."

The fossil that led to the revelatory discovery was found in in 2011 in a deposit along a river the city of Grande Prairie, in west-central Alberta, Canada.

Bell, along with this colleagues, including Federico Fanti from the University of Bologna, Italy, knew when they uncovered the Edmontosauraus fossil that they had found something significant.

The find was made all the more remarkable because of the unlikelihood of a fleshy skin accessory becoming mummified and surviving millions of years.

"An elephant's trunk or a rooster's crest might never fossilize because there's no bone in them," Bell said in a statement. "This is equivalent to discovering for the first time that elephants had trunks. We have lots of skulls of Edmontosaurus, but there are no clues on them that suggest they might have had a big fleshy crest. There's no reason that other strange fleshy structures couldn't have been present on a whole range of other dinosaurs, including T. rex or Triceratops."

The researchers noted that it will be difficult to determine the function of the prehistoric cockscomb.

In modern-day roosters, the appendage is used as a way of attracting mates.

"We might imagine a pair of male Edmontosaurus sizing each other up, bellowing, and showing off their head gear to see who was the dominant male and who is in charge of the herd," Bell said, but he added that at this point, it's pure speculation. It's unlikely that we will ever know.

Bell, Fanti and their colleagues published their findings in the journal Current Biology.