An herbivorous dinosaur is a dinosaur that only eats plants. The majority of dinosaur species were herbivores, including the brachiosaurus, stegosaurs, triceratops, astrodon, ankylosaurus and ornithopsis.
It has been suggested that approximately 65 percent of dinosaur species were herbivores, where roughly 35 percent were carnivores, or theropods. Examples of well-known carnivorous dinosaurs are the tyrannosaurus rex, or T-rex, and velociraptor. A very small number of dinosaur species were omnivores, meaning they ate both plants and animals. Most herbivorous dinosaurs were actually omnivores in a sense, because they often accidentally ingested small animals and insects when eating plants.
In all animal populations, there tend to be more herbivores than carnivores. More plant eaters are needed at the bottom of the food chain in order to supply food and energy to carnivores at the top of the food chain.