A new raven-sized fossil bird, showing clear evidence of the close relationship between theropod dinosaurs and birds, has been discovered on the island of Madagascar by scientists working under a National Science Foundation (NSF) grant. The fossil bird is 65 to 70 million years old and dates from the Late Cretaceous period. It was discovered in 1995 by an international team of paleontologists led by David Krause and Catherine Forster of the State University of New York at Stony Brook. The scientists have named the new discovery Rahona ostromi, meaning "Ostrom's menace from the clouds."

The forearm bone of Rahona is long and shows evidence of well-developed feathers, indicating it was a capable flyer. But unlike most birds, Rahona also had a long, bony tail and sported a large, sickle-like killing claw at the end of a thick second toe on the hind foot. This unique toe and claw is identical to the one carried by a group of fast, predacious theropod dinosaurs called "maniraptorans." It is these maniraptoran dinosaurs (a group that includes Velociraptor and Deinonychus), that many, but not all, scientists believe gave rise to birds.

"This new fossil is one of the strongest last nails in the coffin of those who doubt that dinosaurs had anything to do with the origin of birds," Forster said. She added, "Rahona was at the base of the bird family tree, right next to Archaeopteryx. It had a feathered wing and many bird features in its hips and legs, including a perching foot. But, it also kept the big killing claw of its theropod ancestors." Paleontologists have long suspected that theropod gave rise to birds, and the presence of this "maniraptoran" toe and claw on the Malagasy bird "clinches it for us. This discovery lends a lot of weight to the idea that birds are a side-branch of the theropod family tree," she added.

The discovery was made during one of a series of ongoing paleontological expeditions in Madagascar, funded by NSF. In addition to Rahona, the scientific team discovered an array of well-preserved skeletal remains of other fossil animals, including theropod and sauropod dinosaurs, mammals, turtles, snakes, crocodiles and other birds. Another expedition to Madagascar is planned for this summer.