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Fossil’s ‘Killing Claw’ Supports Theory That Birds Descended From Dinosaurs Animal Found In Madagascar ‘Was At The Base Of The Bird Family Tree’

Thu., March 19, 1998

The fossil of a raven-sized bird with dinosaur-like features has been unearthed in Madagascar from a rock formation deposited more than 65 million years ago, researchers report.

The fossils, of a type never before seen, include the wing bones of a bird, but also a long tail and “a huge, sickle-shaped killing claw” that resemble such features in meat-eating theropod dinosaurs, said Catherine A. Forster of the State University of New York at Stony Brook School of Medicine.

“This animal gives powerful new evidence to support the theory that birds descended from dinosaurs,” Forster said Tuesday. She said the fossil may be “the strongest last nails in the coffin” for those who doubt that birds evolved from dinosaurs.

A report on the study by Forster and her colleagues will be published on Friday in the journal Science.

Forster said the new bird species has been named Rahona ostromi, which translates from the native Madagascar language to mean “Ostrom’s menace from the clouds.” A scientist named John Ostrom was an earlier proponent of the idea that birds evolved from dinosaurs.

The bird fossil was found in a rock quarry among a number of other dinosaur-era fossils on the Indian Ocean island of Madagascar off the east coast of Africa.

Among the fossils, said Forster, were the bones of more advanced birds that lived during the same time and at the same place as Rahona.

She said that Rahona was much more primitive, closely resembling Archaeopteryx, an animal that lived 150 million years ago and is the earliest known true bird.

“Rahona was at the base of the bird family tree, right next to Archaeopteryx,” said Forster. “It had a feathered wing plus many bird features in his hips and legs, including a perched foot.”

But Rahona also had that big killing claw on the second digit of its feet. Such a claw is also found on fossils for dinosaurs like the velociraptor, a meat eater that walked on his hind legs and attacked with his claw and a mouth full of teeth.

Forster said that the Rahona fossil deposit does not include the head, but she assumes because of the killing claw that the bird was a meat eater.

The bird had a wing span of at least 2 feet, she said, and there were bumps along the side of one wing bone that are seen in the bones of modern birds. Forster said these bumps are where feathers grow, suggesting that Rahona had a wide, feathered wingspan.


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