Primitive protoptitsy fly, using not two, but four wings. The lower pair of wings in their descendants eventually disappeared. This is evidenced by the fossils of several species of ancient birds, according to paleontologists who published their data in the journal Science.
The emergence of the first protoptits dated around the second half of the Jurassic period. Feathers over millions of years of evolution, gradually transformed from an instrument used for heating and attract females to a device that allowed the holders to learn a new environment - the air. Thus, the device of wings and feathers gradually improved and now allows some modern birds most of my life to spend in the air.
A group of Chinese paleontologists from the University of Lini led by Xu Xing (Xing Xu) found that for the first flight of the birds once used four wings by doing a comparative analysis of the structure of feathers several protoptits, including konfutsiornisov, and birds belonging to the genus Sapeornis and Yanornis. Xu and his colleagues in their work analyzed the anatomy of birds, as well as restored the shape and structure of the feathers that were attached to their limbs.
Legs most ancient birds, as it turned out, were covered unusual plumage. Their basis is in contrast to the modern birds were not warm-soft fluff, and suitable for the flight feathers are tough. With the help of a computer the authors restored the approximate appearance of birds and check what will be the impact of the second pair of wings on the aerodynamics of birds and their ability to fly.
"Chetyrehkrylye" protoptitsy, as emphasized by paleontologists were able to fly, but at the same time noticeably inferior to modern birds in the ability to fly. Motley species composition of ancient birds, which belonged to the fossilized skeletons indicates that the flight mode was probably the main way to the conquest of the sky in the Mesozoic era. The ancestors of birds then abandoned it in favor of a more maneuverable and fast flight, carried out with a single pair of wings, scientists noted in conclusion.