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,
Intracellular digestion digested by the lysosome's enzymes. Intracellular digestion can also refer to the process in which animals that "lack" a digestive tract bring food items into the cell for the purposes of digestion for nutritional needs. This kind of intracellular digestion occurs in many unicellular protozoans, in Pycnogonida, in some molluscs, Cnidaria and Porifera. There is another type of digestion, called extracellular digestion. In amphioxus, digestion is both extracellular and intracellular. Intracellular digestion is divided into heterophagic digestion and autophagic digestion. These two types take place in the lysosome and they both have very specific functions. Heterophagic intracellular digestion has an