Bell had found a fleshy dome extending off of the duckbill's skull -- something that had never been seen before. The dome included no bones and extended from the front of the eye sockets to the back of the head. It was almost 8 inches (20 centimeters) tall at its highest point and about 13 inches (33 cm) long.
"You can actually see the wrinkles in the skin that indicate that it had some flexibility to it," Bell said.
In modern birds, such combs are typically used for sexual display. They're found in both sexes in birds, so the presence of the comb tells researchers nothing about their dinosaur specimen's sex. The bones they do have belong to the neck and head, and don't reveal sex either.
"What we need to find now are additional specimens that show this structure, and perhaps by comparing their sizes or relative development, we might get an idea of their sex," Bell said.
It's not clear whether the comb is a feature only of E. regalis or if other duckbills might have had similar fleshy accessories. Skin associated with the head may not preserve well, meaning that other combs have vanished without a trace, Bell said. Or, they may have been overlooked. In the past, paleontologists considered skin impressions less interesting than bones, so they ignored them.
"People would actually remove and destroy the skin that's been preserved in order to get to the bones," Bell said.
Modern preparation has the potential to lead to a deeper understanding of dinosaurs, he said. "There's going to be no end of new and very surprising discoveries to come," Bell said.
The researchers report their findings today (Dec. 12) in the journal Current Biology.
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