Protarchaeopteryx had long legs, and could have been a quick runner. It had well-developed, vaned feathers extended from a relatively short tail; the hands were long and slender, and had three fingers with sharp, curved claws. Its bones were hollow and bird-like, and it possessed a wishbone. At around 1 metre (3.3 ft) in length, it would have been larger than Archaeopteryx. Protarchaeopteryx also had symmetrical feathers on its tail. Since modern birds that have symmetrical feathers are flightless, and the skeletal structure of Protarchaeopteryx would not support flapping flight, it is assumed that it was flightless as well. It has been suggested that it could have had an arboreal lifestyle, jumping from tree limbs and using its forelimbs for a form of parachuting.