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 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 as a time traveller who investigates and encounters dinosaurs in the wild. The specials are known only by their individual titles (with the subtitle 'A Walking With Dinosaurs Special/Trilogy') on-screen; The umbrella title 'Chased by Dinosaurs' was used to market the series in the United States. The production company Impossible Pictures and producer Jasper James would produce