Dinosaurs may have had the ability to fly earlier than previously believed and scientists are now better bridging the gap between them and modern birds, the Los Angeles Times reported.
The new study, published Wednesday in Nature, suggests dinosaurs other than Archaeopteryx had the neurological capacity for flight. Lead author Amy Balanoff, a paleontologist at Stony Brook University, digitally filled in dinosaur skulls to image their brains.
"We used CT technology to digitally fill in skulls," she said. The skulls had impressions in the bone made by the brain, which made it possible to create a virtual "cast of what the brain would have looked like."
The research team used the CT scans of the dinosaur skulls and compared them to those of modern birds. Then they used 3-D modeling technology to reconstruct what the brains looked like and calculated the volume based on body size.
"The story of brain size is more than its relationship to body size," co-author Gabriel Bever, of the New York Institute of Technology, told BBC News. "If we also consider how the different regions of the brain changed relative to each other, we can gain insight into what factors drove brain evolution as well as what developmental mechanisms facilitated those changes."
In hopes of better understanding the modern bird's ancestry, Balanoff and her team studied the Archaeopteryx and its close relatives, such as the Deinonychosaurus. The team found the brains to increase in size as they evolved to look less like dinosaurs and more like birds.
This could mean that the dinosaurs were not equipped for full flight, but rather something as simple as gliding from tree to tree, Balanoff told the Times. "These large brains meant they probably had the neurological capacity to navigate in complex environments."
UC Berkley paleontologist Kevin Padian said dinosaurs before the Archaeopteryx did not have the anatomy to fly. He also said brain size could not be relied upon to provide all the answers.
"I have a big brain and I can't fly," he said. "Many animals with really tiny brains, such as ants, are capable of complex behavior."
Adrian Thomas, a zoology professor from Oxford University, said the discovery was not a surprise but made the evolution path more complicated.
"Rather than a straight [evolutionary] path that led Archaeopteryx to birds, the picture now is that there were lots of dinosaurs exploiting the advantages of gliding and flight. The birds are the ones that carried on successfully to the present day," Prof Thomas told BBC News. "So it is interesting, but not a great surprise, to see increased brain size in these dinosaurs associated with their highly agile lifestyles."
