Dinosaurs Sprouted Wings Earlier Than Previously Thought
by Michael Balter
Dinosaurs still walk—and fly—among us: We call them birds. Most paleontologists think birds descended from a group of winged dinosaurs, and thus dinos never went completely extinct. But where did the wings come from? New discoveries from Canada suggest that both wings and feathers arose earlier in dinosaur evolution than previously thought, possibly to attract members of the opposite sex or to protect hatching baby dinos.
Although many details of the origins of birds and winged flight are fiercely debated, researchers generally agree that birds belong to a group of dinosaurs called maniraptorans, some of which had feathers and wings and could probably fly.Microraptor, discovered in China, is a leading example of such a dino flyer. Indeed, almost all feathered dinosaurs have been found in the Liaoning and Inner Mongolia regions of northeastern China, where finely grained lake deposits provide excellent preservation of dinosaur fossils; the few exceptions come mostly from Germany.
But the restriction of these discoveries to such a limited geographical area has left a gap in the fossil record, leaving paleontologists to wonder whether wings and feathers might have evolved in dinosaur groups older than the maniraptorans. A team led by Darla Zelenitsky, a geoscientist at the University of Calgary in Canada decided to take a closer look atthree specimens of a dinosaur called Ornithomimus edmontonicus housed at the Royal Tyrrell Museum of Paleontology near Drumheller, Canada. Two of the specimens, encased in hard blocks of coarse-grained sandstone, were found by a resident of Drumheller in 2008 and 2009; the third had been in the museum’s collections since the 1990s…
(read more: Science NOW)
(images: T - Julius Csotonyi; B - Royal Tyrrell Museum)
