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
Chased by Dinosaurs an extended twenty-one minute version of the interview present on the UK disc, with the additional material relating to "Sea Monsters". "Chased by Dinosaurs" is a spin-off of the following series of BBC documentaries: "Chased by Dinosaurs" is one of the "Walking With... series" specials, that also include: The following are similar programs, produced by the BBC: Chased by Dinosaurs Chased by Dinosaurs is a five-episode spin-off of the BBC program "Walking with Dinosaurs" which originally aird on BBC One during Christmas 2002 and November 2003. In a departure from the series usual format, these specials feature zoologist Nigel Marven