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 on the main slab. Both arms are preserved close to their natural articulation with the shoulder girdle, though displaced. The ulna is more robust and curved than the slender radius. A confusing jumble of metacarpals has led some researchers to conclude the beginning of fusion between carpals and metacarpals; this has been rejected by later researchers. Most manual bones of the right wing are missing, and the left wing preserves two metacarpals, the semilunate carpal, and two long, slender phalanges with large, strongly-curved claws. The missing third finger led Owen to conclude a two-fingered hand for "Archaeopteryx" in his original