Dinosaur mass of adults among these dinosaurs suggest that the eggs were primarily brooded by the male, and that the young were highly precocial, similar to many modern ground-dwelling birds. Some dinosaurs are known to have used gizzard stones like modern birds. These stones are swallowed by animals to aid digestion and break down food and hard fibers once they enter the stomach. When found in association with fossils, gizzard stones are called gastroliths. The discovery that birds are a type of dinosaur showed that dinosaurs in general are not, in fact, extinct as is commonly stated. However, all non-avian dinosaurs,
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