Researchers came to their conclusion after studying three well-preserved fossil specimens of the extinct creature, called Sinosauropteryx.
They were able to discern the dinosaur’s colour patterns, showing that it had a banded tail and “counter-shading” – where animals are dark on top and lighter on their underside.
The study appears in Current Biology.
The bandit mask pattern is seen in numerous animals today, from mammals – such as raccoons and badgers – to birds, such as the nuthatch.
“This is the first time it’s been seen in a dinosaur and, to my knowledge, any extinct animal that shows colour bands,” co-author Fiann Smithwick, from Bristol University, told BBC News.
There are a variety of ideas about why animals carry the bandit mask pattern. And the reasons might differ between individual species.
“In raccoons and badgers, it’s an advertisement of the fact that they’re aggressive,” said Dr Smithwick, adding: “If you’re a predator and you mess with them, they’re going to fight back.”
“We think that’s probably unlikely in Sinosauropteryx because there’s no real anatomical evidence that it could have defended itself well. It’s a small dinosaur and quite gracile (lightly built).