How can scientists work out what dinosaurs ate 2 reasons?

Answer 1

1. By looking at the animal's teeth and jaws, they can tell what it ate. Sharp teeth mean it ate meat, leaf shaped teeth mean it plucked leaves and swallowed them without chewing, and molar-like teeth meant the animal chewed plant material, potentially tough vegetation.
2. In very well preserved specimens, there may be stomach contents. Tiny bones in the stomach of Coelophysis specimens show that they ate small, lizard like animals.