The suborder Hystricomorpha encompasses a diverse group of rodents that include guinea pigs, chinchillas, porcupines, and capybaras. There are several synonyms for this suborder, including Caviomorpha, which refers to the group of rodents that possess a unique arrangement of muscles in their jaws, as well as simply "New World rodents" due to their exclusive distribution in the Americas. Other synonyms include Histricomorpha, Hystricimorpha, and Hystricomorphic rodents. Despite their various names, the animals in this suborder share distinctive physical and behavioral characteristics that have adapted for living in a variety of habitats, from grasslands to rainforests.