Photo: Julius T. Csotonyi

A technique known as laser-stimulated fluorescence imaging has allowed researchers to reconstruct a Jurassic-era dinosaur with unprecedented accuracy, which may also unlock clues to the origin of flight.

University of Hong Kong researchers conducted laser-stimulated fluorescence imaging on specimen samples of Anchiornis—a feathered bird with four wings and “drumstick-shaped” legs first discovered in northeast China in 2009.

The imaging technique highlighted soft tissues alongside the bones of the dinosaur that are not visible under any other conditions. The laser light shines over the specimen, making the fossil sample glow, and long-exposure photos are taken in a dark room to illuminate the previously unseen details.

The team examined nine specimens, and revealed their findings in Nature Communications this week.

Anchiornis lived 160 million years ago, and only stood at about 1-foot high. The species did not compete with other top predators, and likely consumed insects and small lizards.

“Laser-stimulated fluorescence (LSF) imaging can broaden the scope of data available from fossils by revealing morphological details that are otherwise invisible under white or ultraviolet light conditions,” wrote the authors.

Anchiornis translates to “near-bird,” and the study authors note that the dinosaur had a wing structure very similar to modern birds. For example, the LSF imaging showed Anchiornis had patagium, a fold of skin that links the upper arm to the lower, a feature seen in bats and living birds today.

This discovery suggests that Anchiornis may have been capable of flying, but the researchers can not definitively conclude that was the case as some other birds equipped with patagium are completely flightless.

The first Anchiornis fossils were unearthed inChina in 2009. Hundreds of specimens have been collected and studied since then. Previous research determined that the bird-like dino had four wings and was covered in black and gray feathers, with highlights of white. Red feathers crowned the top of its head.

The species has had a history of mistaken identity, first being described as a bird. Since its discovery, different groups of authors have shown evidence supporting its bird identity, while others have contradicted it, according to the study’s co-author Michael Pittman, of the University of Hong Kong.

Other features of Anchiornis that resemble birds today include its “drumstick” legs, long forearms and foot scales that are similar to that of chickens.

The wing of Anchiornis under laser-stimulated fluorescence imaging. Photo: Wang XL, Pittman M et al. 2017