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,
Physiology of dinosaurs endotherms, the larger forms could have been inertial homeotherms, or that many dinosaurs could have had intermediate metabolic rates. The earliest dinosaurs were almost certainly predators, and shared several predatory features with their nearest non-dinosaur relatives like "Lagosuchus", including: relatively large, curved, blade-like teeth in large, wide-opening jaws that closed like scissors; relatively small abdomens, as carnivores do not require large digestive systems. Later dinosaurs regarded as predators sometimes grew much larger, but retained the same set of features. Instead of chewing their food, these predators swallowed it whole. The feeding habits of ornithomimosaurs and oviraptorosaurs are a mystery: although