Scientists have scoured fossil records to find out one of the greatest mysteries of the “origin of bird”. They have uncovered surprising twists in the evolution of birds from their flightless ancestors. The quest to understand the origin of birds and other animals began in earnest over 150 years ago.
In 1860, a marvelous creature was unearthed from a limestone quarry in Germany. It was a 150-million-year-old fossil named Archaeopteryx. It preserves in fine detail feathers along the wing just like those we see in living birds, and feathers along the tail. But the bony feathers tell a very different story. It has teeth in the jaw, tiny claws preserved in a hand, and a long bony tail, lacking in living birds but present in things we think of traditionally reptilian.
Archaeopteryx pointed to a close link between birds and reptiles. But which group of reptiles? Thomas Huxley, an English biologist, was astonished by Archaeopteryx’s resemblance to a turkey-sized dinosaur called Compsognathus. Its hand also had three digits. It had hollow bones and stood on two legs. Similarities like these led Huxley to propose that birds are related to the branch of reptiles called dinosaurs.
But other scientists questioned this conclusion. Birds appeared so different from dinosaurs, and some characteristic features of birds – like wishbones – seemed to be missing from dinosaurs, but were present in other reptiles. Most of the dinosaurs that the public knows about were really big. Scientists thought dinosaurs were cold-blooded and slow moving like other reptiles. People couldn’t imagine dinosaurs being agile and hopping around. They look at these big giant things and they lumber. There’s no way to relate them to birds.
Then, in 1963, John Ostrom, an American paleontologist, discovered fossils in the badlands of Montana that challenged that view. (Floro Mercene)