According to Kenneth Dial, author of the report, the transition from ground travel to flight may have required a "ramp-up" phase in which rapid movement of the animals' front appendages actually forced its body downward to gain more foot traction as it made its way up increasingly vertical slopes.
"The big dilemma has been, 'How do you explain the partial wing?,'" says Dial, who is a professor of vertebrate morphology and ecology. "It turns out the proto-wings--precursors to wings birds have today--actually acted more like a spoiler on the back of a race car to keep the animal sure-footed even while climbing up nearly vertical surfaces," he said.
"The development and role of movement in animals is critical to every aspect of their lives, " says William Zamer of the National Science Foundation (NSF), the agency that funded the study. "The results may also one day help humans design better vehicles for both land and air travel."
NSF is an independent federal agency that supports fundamental research and education in all fields of science and engineering.
The evolution of flying vertebrates has been a bone of contention since the 1800's. One school, which embraced the cursorial theory, argued that two-legged, ground-dwelling animals developed feathered wings that allowed them to become airborne. The opposing school, which favored the arboreal theory, held that flight originated in tree-dwelling animals that leapt from limb to limb and eventually developed gliding structures to soften their landings. For a century-and-a-half, each ca
Contact: Leslie Fink
National Science Foundation