BEIJING, Feb. 13 (Xinhua) -- The fossil of sparrow-sized pterodactyl has been discovered in China's northeast Liaoning Province, which is hailed by scientists as the smallest of its particular group.

    The fossil was found in the western part of Liaoning, a region that was forested when the animal - dubbed Nemicolopterus crypticus, or "hidden flying forest dweller" - lived there about 120 million years ago, China Daily reported Wednesday.

    The finding is exciting because it's the smallest toothless pterosaur in the world, the English newspaper quoted Wang Xiaolin, leading paleontologist of an international research team who found the fossil.

    It "opens a brand new chapter in the history of the evolution of flying vertebrates", Alexander W. A. Kellner of the National Museum of the Brazilian city's Federal University was quoted as saying.

    "Because they were flying animals, their fossils are extremely rare. So, discoveries such as this are fundamental to the understanding of evolution of these winged vertebrates," he said.

    The newly-found pterodactyl is a small, toothless creature with unexpectedly curved toes. It is assumed to fed on insects. The pterodactyl found in Liaoning seems to be the only one living in trees, according to the scientists.

    Pterodactyls are best known from giant examples of the ancient flying reptiles, and most specimens have been uncovered in coastal areas. All the pterosaurs of earlier periods (Late Triassic to Jurassic) found so far had teeth. And the toothless ones who lived in the Cretaceous period were usually quite big, with their bodies, including their "wingspan", stretching from 6 to 12 meters. Most pterosaurs usually lived near the sea or lake.

    The first fossilized pterosaur was found in Germany about 200 years ago, half a century before the first dinosaur fossil was identified.

    Since then, researchers have found pterosaur fossils across the world, the largest being as big as a jumbo jet and the smallest the size of a sparrow. So far about 150 species of the flying reptiles have been identified and named.