Ornithopods were a group of herbivorous dinosaurs known for their bird-like features. They lived during the Late Jurassic to the Late Cretaceous periods and included well-known species like Iguanodon and Hadrosaurus. These dinosaurs had strong hind limbs, allowing them to walk on two legs, and some could also move on all fours. Ornithopods were characterized by their beaks and specialized teeth, which helped them chew tough plant material. They often traveled in herds, providing safety in numbers. Their diverse adaptations allowed them to thrive in various environments, making them one of the most successful dinosaur groups.