Mummified Duck-Billed Dinosaur Reveals Species Had A 'Rooster Comb,' Offering New Clues About Behavior
A duck-billed dinosaur, once the most common giant lizard in North America, had a flabby piece of ornamental flesh on the top of its head, scientists have learned. After discovering a mummified Edmontosaurus regalis in Canada, researchers in Australia and Italy say the dinosaur, one of two duck-billed species, had something like a rooster's comb, probably for mating or communication.
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"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," says Phil Bell, of the University of New England, in a press release. "It also raises the thought-provoking possibility of similar crests among other dinosaurs."
Much is known about the Edmontosaurus regalis, which you can think of as a kind of 40-foot-long deer. The Australian paleontologists also compared them to kangaroos. They were extremely common and extremely harmless (there were no headlights 65-75 million years ago, when duck-billed lizards roamed the prairies). But until this well-preserved fossil was discovered in Alberta, scientists had never considered the possibility that dinosaurs might have rooster-like appendages. Now that the phenomenon has been sufficiently described in the journal Current Biology, the speculation race begins to figure out for what purpose it evolved.
In roosters, the bright red "cock's comb" is "a way to get the girls," explains the journal. Of course, it's unclear what color the regalis comb would have been. Cranial ornaments, the researchers note, are found in other dinosaurs. You may remember this guy, Parasaurolophus, from Jurassic Park. Its recognizable crest was basically a resonance chamber. Not the case here; it's not connected to the nasal passage. "The fleshy comb in Edmontosaurus necessitates an alternative explanation most likely related to either social signaling or sexual selection," Bell and his colleagues write. These were herding animals, like cattle, and "social signaling" could mean that the leader of the herd indicated dominance by his comb, Bell tells National Geographic.
The discovery also forces scientists — and artists and filmmakers — to consider reimagining other dinosaurs, "including T. rex or Triceratops," Bell says. Because fleshy tissue almost never fossilizes except by a rare stroke of luck, hundreds of other specimens may be incomplete without our knowledge. "This is equivalent to discovering for the first time that elephants had trunks," Bell said. "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."
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