Large Vegetarian Dinosaurs Ate Shelled Animals Too, Their Feces Suggests

The largest dinosaurs that roamed the Earth before a mass extinction event caused by an asteroid strike wiped them out (and 75 percent of all life on the planet at the time) were all herbivores, that is, they were vegetarians. But that well-established fact is being challenged by a new finding: at least some of the largest herbivore dinosaurs also ate crustaceans, or shelled animals. Ancestors of modern-day crustaceans -- which have hard exoskeletons, such as crabs, lobsters, shrimp and crayfish -- were rich sources of proteins and calcium, and ingesting them could have been linked to dinosaurs' reproductive activities, according to researchers who made the discovery in Utah's Grand Staircase-Escalante National Monument. "From what we know about dinosaurs, this was a totally unexpected behavior. It was such a surprising discovery we wondered what the motivation could have been," Karen Chin, curator of paleontology at the Museum of Natural History in the University of Colorado, Boulder, said in a statement Thursday.