Fossil showing the wing and feathers of the prehistoric bird Confuciusornis. Credit: Yosef Kiat
Phys.org has a story about flying dinosaurs. A new paper in the journal PNAS looked at hundreds of feathers in museum collections to determine which feather characteristics were common to flying birds. These characteristics were then used to create "rules", which when applied to fossil dinosaur feathers might predict which dinosaurs were able to fly. The research was performed by two Field Museum scientists, paleontologist Jingmai O'Connor Associate Curator of Fossil Reptiles and ornithologist Yosef Kiat, a postdoctoral researcher at the Field.
By applying the information about the number of primary feathers to the overall bird family tree, Kiat and O'Connor also found that it takes a long time for birds to evolve a different number of primary feathers. "This trait only changes after really long periods of geologic time," says O'Connor. "It takes a very long time for evolution to act on this trait and change it."
In addition to modern birds, the researchers also examined 65 fossil specimens representing 35 different species of feathered dinosaurs and extinct birds. By applying the findings from modern birds, the researchers were able to extrapolate information about the fossils. "You can basically look at the overlap of the number of primary feathers and the shape of those feathers to determine if a fossil bird could fly, and whether its ancestors could," says O'Connor.
For instance, the researchers looked at the feathered dinosaur Caudipteryx. Caudipteryx had nine primary feathers, but those feathers are almost symmetrical, and the proportions of its wings would have made flight impossible. The researchers said it's possible that Caudipteryx had an ancestor that was capable of flight, but that trait was lost by the time Caudipteryx arrived on the scene.
Since it takes a long time for the number of primary feathers to change, the flightless Caudipteryx retained its nine primaries. Meanwhile, other feathered fossils' wings seemed flight-ready— including those of the earliest known bird, Archaeopteryx, and Microraptor, a tiny, four-winged dinosaur that isn't a direct ancestor of modern birds.
Fossil Friday also did a segment on this research.
An Archaeopteryx fossil, complete with visible imprints of its feathers. Credit: Shutterstock
Not all birds can fly. Penguins, ostriches, and kiwis are some famous examples.
It’s pretty easy to figure out if a living bird can fly. But it’s a bit tricker when it comes to extinct birds or bird ancestors, like dinosaurs. Remember, all birds are dinosaurs, but not all dinosaurs evolved into birds.
Scientists at Chicago’s Field Museum wanted to figure out if there was a way to tell if a dinosaur could fly or not. They found that the number and symmetry of flight feathers are reliable indicators of whether a bird or dinosaur could lift off the ground.
Ira talks with two of the study’s co-authors about their research and how it might help us understand how dinosaur flight evolved. Dr. Yosef Kiat is a postdoctoral researcher and Dr. Jingmai O’Connor is the associate curator of fossil reptiles at The Field Museum in Chicago.
