A technique using high-powered lasers to reveal hidden soft tissue in fossils is bringing insight into one of the major evolutionary transitions: small feathered dinosaurs taking flight as birds.

Scientists said on Tuesday they had used the method on fossils of the feathered birdlike dinosaur Anchiornis, which was the size of a chicken and lived in China about 160 million years ago. They found it had drumstick-shaped legs, arms similar to the wings of some modern birds that soar or glide, and a long tail.

There has been a debate over whether or not to classify this Jurassic Period creature as a bird, considering its avian features. Either way, it boasts numerous skeletal and soft-tissue characteristics found in birds and lived close to the time when birds diverged from their dinosaur ancestors.