Bird

Many - see section below.

Other anatomy

Birds possess a ventriculus, or gizzard, that is composed of four muscular bands that act to rotate and crush food by shifting the food from one area to the next within the gizzard. Depending on the species, the gizzard may contain small pieces of grit or stone that the bird has swallowed to aid in the grinding process of digestion. For birds in captivity, only certain species of birds require grit in their diet for digestion. The use of gizzard stones is a similarity between birds and dinosaurs, which left gizzard stones called gastroliths as trace fossils.

Related Topics:
Gizzard - Digestion - Gastrolith - Trace fossil

~ ~ ~ ~ ~ ~ ~ ~ ~ ~