Some carnivorous and omnivorous farmed fish species are fed wild forage fish. These are eaten by herbivorous fish which in turn are eaten by larger carnivorous fish. Food habits range from strictly carnivorous to strictly herbivorous. Dinocephalians included herbivorous, carnivorous, and omnivorous forms. They include carnivorous, herbivorous, and omnivorous forms. Skinks are generally carnivorous and in particular insectivorous. Tertiary consumers can be either fully carnivorous or omnivorous. This includes the development and growth of carnivorous and herbivorous species. Such habitats also have many species of wild orchids and carnivorous plants. Most carnivorous plants selectively feed on specific prey. They are a widely distributed and diverse parvorder of carnivorous marine mammals. Dogs are considered to be omnivores with a carnivorous bias. Another important area of symbiosis between carnivorous plants and insects is pollination. Tyrannosaur tooth marks are the most commonly preserved feeding traces of carnivorous dinosaurs. Alligator snapping turtles are opportunistic feeders that are almost entirely carnivorous.