It may not have been a champion aviator, but the famous dino-bird Archaeopteryx was fully capable of flying despite key skeletal differences from its modern cousins, though not exactly gracefully, according to a new study. Think Wright Brothers, not F-22 fighter jet.

Scientists said on Tuesday they examined Archaeopteryx's wing architecture using state-of-the-art scanning and compared it to a range of birds, closely related dinosaurs and the extinct flying reptiles called pterosaurs. They concluded it could fly in bursts over relatively short distances like pheasants, peacocks and roadrunners.

Birds evolved in the Jurassic period from small feathered dinosaurs, and represent the only dinosaur group to have survived the mass extinction event 66 million years ago.

Crow-sized Archaeopteryx, which lived about 150 million years ago in a tropical archipelago that is now Bavaria, combined primitive dinosaur characteristics with traits seen in modern birds.

Its fossils were first discovered in 1861 and it was long considered the earliest-known bird, though there is now a spirited scientific debate about defining the first birds.

The Munich specimen of the Archaeopteryx. It shows a partial skull, top left, shoulder girdle and both wings slightly raised, most left to centre left,, as well as the ribcage, centre. Imprints of its wing feathers are visible radiating from below the shoulder. (ESRF/Pascal Goetgheluck)

"Many researchers have assumed that Archaeopteryx exhibited a very primitive way of flying that would have been equivalent to that of gliding from tree to tree, like extant flying squirrels do," said paleontologist Sophie Sanchez of Uppsala University in Sweden. "It, therefore, is a big surprise to actually recognize adaptations consistent with active flight."

"We are convinced that this presents the best indication for active flight in Archaeopteryx brought to light in the last 150 years," added paleontologist Dennis Voeten of the European Synchrotron Radiation Facility in France, though he called it "a poor flyer."

Archaeopteryx boasted teeth, a long tail and had no bony, keeled sternum where flight muscles attach. Its flight capabilities may have enabled Archaeopteryx to escape predators or fly among islands

The researchers focused on a cross-section of the wing bones and their density of blood vessels. They found similarities to birds capable of short-distance flight, not gliding and soaring varieties like birds of prey.

Archaeopteryx was likely able to take off from the ground, but must have used a unique flying style, Sanchez said. It lacked important traits in the shoulders of modern birds, making it impossible to beat its wings the way they do.

"We propose that it would have been able to use its wings to propel its body in a fashion that superficially resembles the stroke of butterfly swimmers," Sanchez said.

The research was published in the journal Nature Communications.