National Geographic reports that paleontologists in China have discovered the fossil remains of a four-winged dinosaur with fully developed, modern feathers on both the forelimbs and hind limbs. The new species, Microraptor gui, provides yet more evidence that birds evolved from dinosaurs, and could help a lot in explaining how dinosaurs evolved into birds. An article in the journal Nature suggests that that the species is an early ancestor of birds that probably used its feathered limbs, along with a long, feather-fringed tail, to glide from tree to tree, much like flying squirrels do today.