Physiology of dinosaurs and that this was a feature they shared with birds. In 2007 Oliver Wings reviewed references to gastroliths in scientific literature and found considerable confusion, starting with the lack of an agreed and objective definition of "gastrolith". He found that swallowed hard stones or grit can assist digestion in birds that mainly feed on grain but may not be essential—and that birds that eat insects in summer and grain in winter usually get rid of the stones and grit in summer. Gastroliths have often been described as important for sauropod dinosaurs, whose diet of vegetation required very thorough digestion, but
The Dinosaurs! 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 an