Wind Tunnel Used to Study Evolution of Dinosaur 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 by scientists at from the University of Southampton, shedding light on how feathery dinosaurs adapted to the skies.

The microraptor is the first known theropod, or two-footed dinosaur, to have feathers on its arms, legs and tail, providing five surfaces or "wings" with which it could fly, or at least glide, through the air. There is an increasing consensus among paleontologists that modern birds evolved from small, feathered dinosaurs, but how, exactly, remains unknown.

By placing the microraptor model in the wind tunnel and running flight simulations, the researchers were able to show that even though the microraptor's wings were rudimentary to modem birds, the creatures could still sustain slow glides from low heights.

"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," said Gareth Dyke, a senior lecturer in vertebrate palaeontology at the University of Southampton and co-author of the study, which was published in the journal Nature Communications.

"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," Dyke said.

Roeland de Kat, study co-author and research fellow in aerodynamics and flight mechanics at University of Southampton, found the wind tunnel simulations enlightening.

"What interests me is that aerodynamic efficiency is not the dominant factor in determining Microraptor's glide efficiency," de Kat said. " However, it needs a combination of a high lift coefficient and aerodynamic efficiency to perform at its best."