Physiology of dinosaurs way as sauropods. The pachycephalosaurs had small heads and weak jaws and teeth, but their lack of large digestive systems suggests a different diet, possibly fruits, seeds, or young shoots, which would have been more nutritious to them than leaves. On the other hand, ornithopods such as "Hypsilophodon", "Iguanodon" and various hadrosaurs had horny beaks for snipping off vegetation and jaws and teeth that were well-adapted for chewing. The horned ceratopsians had similar mechanisms. It has often been suggested that at least some dinosaurs used swallowed stones, known as gastroliths, to aid digestion by grinding their food in muscular gizzards,
The Dinosaurs! release. The Dinosaurs! The Dinosaurs!, American television miniseries produced by WHYY-TV for PBS in 1992, featuring some of the then-modern theories about dinosaurs and how they lived. It aired four episodes from November 22 to November 25, 1992. The program features the age of dinosaurs, from the appearing of the early forms like "Herrerasaurus", to the "Tyrannosaurus" and Ceratopsians of the late Cretaceous. The possibilities whether dinosaurs were active, warm-blooded animals, had parental care, and the theory that they are the ancestors to birds are featured. What caused their extinction is also discussed. Some animated depictions were made to give