London: Scientists have discovered how feathered dinosaurs took to the skies, providing new insight into the evolution of bird flight.
A full-scale model of the feathery Microraptor - a dinosaur pivotal to the debate of just how these ancient precursors to birds took flight - was placed in a wind tunnel, shedding light on how the gigantic creatures learned to fly.
Scientists from the University of Southampton examined the flight performance of the the early Cretaceous five-winged paravian Microraptor.
The first theropod described with feathers on its arms, legs and tail (five potential lifting surfaces), Microraptor implies that forelimb-dominated bird flight passed through a four-wing (`tetrapteryx`) phase and represents an important stage in the evolution of gliding and flapping.
Researchers performed a series of wind tunnel experiments and flight simulations on a full-scale, anatomically accurate model of Microraptor.
Results of the team`s wind tunnel tests show that Microraptor would have been most stable gliding when generating large amounts of lift with its wings.
Flight simulations demonstrate that this behaviour had advantages since this high lift coefficient allows for slow glides, which can be achieved with less height loss.
For gliding down from low elevations, such as trees, this slow, and aerodynamically less efficient flight was the gliding strategy that results in minimal height loss and longest glide distance.
Much debate, centred on the position and orientation of Microraptor`s legs and wing shape turns out to be irrelevant - tests show that changes in these variables make little difference to the dinosaur`s flight.
"Significant to the evolution of flight, we show that Microraptor did not require a sophisticated, `modern` wing morphology to undertake effective glides, as the high-lift coefficient regime is less dependent upon detail of wing morphology," Dr Gareth Dyke, co-author of the study, said.
"This is consistent with the fossil record, and also with the hypothesis that symmetric `flight` feathers first evolved in dinosaurs for non-aerodynamic functions, later being adapted to form aerodynamically capable surfaces," said Dyke.
The study was published in the journal Nature Communications.