For the first time, the fossils of feathered dinosaurs have been found in the Americas—dug up in the Alberta badlands, by a Canadian team. A new study from paleontologists Darla Zelenitsky and François Therrien describe three specimens of 75-million-year-old ornithomimids, two adults and a juvenile. These ostrich-like dinosaurs famously appeared in Jurassic Park, fleeing in a massive flock from a bloodthirsty Tyrannosaurus rex. According to new research, that famous film got it wrong: instead of scales, these dinosaurs would have been coated in down-like feathers, even flapping their wings.
Adult ornithomimids weighed 330 pounds or more, far too heavy to fly. These dinosaurs grew large feathers on their forearms as they matured; their armspan would have measured two metres across, or longer. “We know their wings weren’t used for flight; they’re much too big for that,” says Zelenitsky, an assistant professor at the University of Calgary. Because only adults had wings, they might have been used to show off for potential mates, or maybe to protectively cover their eggs while brooding, she suggests (it isn’t known whether these fossils are male or female). It’s hard to say what colours ornithomimids would have displayed, although Zelenitsky hopes to study that in the future.
Until now, most feathered dinosaurs have been found in China, like the recently discovered Yutyrannus huali, a massive T. rex cousin with plumage. There, feathered dino skeletons have been dug up from ancient lakes and lagoons, which seemed to help preserve evidence of their feathers; but these sorts of locations are rare worldwide. “No one was expecting to find feathers preserved in the types of rocks [in Alberta] because it wasn’t the right type of environment,” Zelenitsky says, but her work has proven otherwise. “Once the news of this discovery spreads, paleontologists will start looking more carefully at specimens they’ve already collected,” looking for evidence of feathers, she predicts. “This is just the tip of the iceberg.”
Of course, not everyone’s happy about all the feathery new dinosaurs turning up. As Maclean’s reported earlier this year, some dino fans miss the old days, when dinosaurs were big, fat, slow and scaly. Our knowledge of dinosaurs is being rewritten, and Canada has a new feathery dinosaur in its past: a large, downy, ostrich-like ornithomimid.
Thursday, October 25, 2012