SoylentNews

lhsi writes:

Abstract: http://link.springer.com/article/10.1007%2Fs10336-014-1098-9

By re-examining a fossil of Scansoriopteryx (which means "climbing wing"), a sparrow-size creature from the Jurassic era, researchers believe that the commonly held belief that birds evolved from ground-dwelling theropod dinosaurs that gained the ability to fly is false. The birdlike fossil is actually not a dinosaur, as previously thought, but much rather the remains of a tiny tree-climbing animal that could glide.

Through their investigations, the researchers found a combination of plesiomorphic or ancestral non-dinosaurian traits along with highly derived features. It has numerous unambiguous birdlike features such as elongated forelimbs, wing and hind limb feathers, wing membranes in front of its elbow, half-moon shaped wrist-like bones, bird-like perching feet, a tail with short anterior vertebrae, and claws that make tree climbing possible. The researchers specifically note the primitive elongated feathers on the forelimbs and hind limbs. This suggests that Scansoriopteryx is a basal or ancestral form of early birds that had mastered the basic aerodynamic manoeuvres of parachuting or gliding from trees.

Their findings validate predictions first made in the early 1900's that the ancestors of birds were small, tree-dwelling archosaurs which enhanced their incipient ability to fly with feathers that enabled them to at least glide. This "trees down" view is in contrast with the "ground up" view embraced by many palaeontologists in recent decades that birds derived from terrestrial theropod dinosaurs.