Dinosaur teeth reveal some were picky eaters
Calcium in fossilized dino teeth determined the animals’ diets
An analysis of tooth enamel from animals that roamed the western United States about 150 million years ago, including (from left) Allosaurus, Apatosaurus, a herd of Diplodocus and two Camptosaurus, suggests the species all ate different parts of plants or animals to coexist.
Bob Walters and Tess Kissinger, National Park Service