The specimen was an extremely well-preserved fossil of Psittacosaurus, with pigment-containing structures called melanosomes that gave clues to the dinosaur’s coloration.
They compared these microraptor melanosomes to those of modern birds and found a close similarity, though not a perfect match, to the iridescent teal feathers found on duck wings.
The scientists then chose 20 feathers from one fossil and found that the melanosomes in all 20 looked alike, so they became pretty sure this dinosaur was one solid color.
And one specimen of the little horned dinosaur Psittacosaurus was even found to have melanosomes in its skin, revealing that the dino was dark on top and light underneath.