Origin of avian flight Origin of avian flight Around 350 BCE, Aristotle and other philosophers of the time attempted to explain the aerodynamics of avian flight. Even after the discovery of the ancestral bird "Archaeopteryx" over 150 years ago, debates still persist regarding the evolution of flight. There are three leading hypotheses pertaining to avian flight: Pouncing Proavis model, Cursorial model, and Arboreal model. "Archaeopteryx", the oldest known ancestor of modern birds, could provide clues to the origin of avian flight. In March 2018, scientists reported that "Archaeopteryx" was likely capable of flight, but in a manner substantially different from that of modern birds.
Specimens of Archaeopteryx that "Archaeopteryx" could have raised its short second toe in a similar manner to its dromaeosaur cousin "Deinonychus", whose second toe bore an enlarged "sickle claw" for probable use in predation. It remains unclear whether "Archaeopteryx" also used its hyperextended toe-claw in a similar fashion or for some other purpose. Taken together, many of the unique features of the skull, feet and coracoid strengthen a close relationship of archaeopterygids to deinonychosaurian theropods. Well-preserved imprints of wing and tail plumage show details of the barbs, but not barbules, and the shafts of 11 primaries can be counted on the right wing.