Fossilization is an incredibly difficult process. Conditions need to be very specific for a deceased organism to last for tens of millions of years. Finding even large bones can be extremely difficult, while finding imprints of soft tissue is the equivalent of hitting the paleontological jackpot. Phil Bell and his team from the University of New England in Australia did just that when they discovered the fossil of a duck-billed dinosaur with a rooster-like comb on top of its head. The results were published in Current Biology.
The fossil was found in Canada and belongs to the species Edmontosaurus regalis, which lived 73-65.5 million years ago. Dinosaurs in this genus are non-avian and they have a duck-like bill, leading to the name hadrosaur. From tip to tail, these were nearly 40 feet (12 meters) long. Also, it now appears that they had an ornamental comb on top of their heads.
Because skin impressions are so rare, the research team wasn’t even looking for them. The large boulder that contained the fossils as being cut into pieces that were more manageable to investigate when the soft tissue imprint was spotted. There is a startling amount of clarity in the impression, which gave the team a very unique opportunity to study soft tissue structures. The skin has a pebble-like texture, which is similar to modern day crocodiles. The tissues around the skull were also very well preserved, which is exceedingly rare. Because this specimen was so well-preserved, the scientists were able to deduce that it had a fleshy crest on top of the head.
Some birds have a fleshy comb on top of their heads that is used for attracting a mate, which leads researchers to believe that E. regalis may have also have used the structure for the same purpose. It wasn’t like other crests on dinosaurs that were bony and may have offered protection or sound amplification. There were visible wrinkles in the impression, which allows scientists to know that it was able to fold and bend. Since combs are found in both genders of birds, this discovery doesn’t allow scientists to decipher anything in that regard of the specimen.
In order to determine if all hadrosaurs had these combs or if it was specific to just E. regalis, more specimens with well-preserved soft tissues would need to be examined. Of course, this is a very tall order and there is the potential that other similar fossils simply don’t exist. Researchers are hopeful that they will be able to learn more about these crests and get a better understanding of the creatures that roamed the Earth 65 million years before us.