By Susan Milius
RALEIGH, N.C. — A rethink of four-winged dinosaurs suggests that the much-debated hind wings stayed tucked under the body until deployed in the air for tight turns to dodge branches or chase prey.
Just what a dinosaur did with well-developed feathers on all four of its limbs has been a puzzle since the 2003 unveiling of roughly 130-million-year-old Microraptor gui fossils from northeastern China. The first reconstruction showed the small dinosaur gliding in the air with all four limbs extended outward. A later proposal lowered the hind-limb feathers for a Wright-Brothers biplane of wings. Both arrangements have drawn criticism.
In a simpler solution, the dinosaur could have kept its hind limbs under its body much of the time until needed for banking in a turn, Justin Hall of the University of Southern California said on October 20 at the annual meeting of the Society of Vertebrate Paleontology. Extending a feathery right leg a bit while veering left, or vice versa, could easily have shrunk the turning radius by a notable amount depending on the leg angle, he and his colleagues calculated.