How Did We Figure Out the Body Temperature of a Dinosaur?

The word "we" in the post title doesn't mean me or you, because I haven't got a clue, but rather scientists who know what temperature many species of dinosaur had when they were alive. I didn't even know those had been discovered at all, much less how they did it. All we have left of those dinosaurs are fossilized bones and a few impressions from skin, feathers, and footprints. But chemical analysis has detected a chemical called bioapatite, which sounds like something that makes you hungry. The study of this molecule tells us that dinosaurs were warm-blooded, or at least many dinosaurs that we know about. That makes them very different from the reptiles we studied in grade school, and more like the birds we barely studied at all. Minute Earth explains the importance of molecular chemistry to the study of paleontology and how some scientists took the temperatures of long-extinxt diosaurs.