Hystricognath rodents are a large group of rodents, with more than 230 species. Species in this group are found in North and South America and in Africa and Asia, although the vast majority of species are found in South America. This groups includes some of the largest rodents, including capybaras and American and Old World porcupines. This group also includes some of the most unusual species of rodents, such as naked mole rats, and some of the most familiar, such as porcupines, guinea pigs, and chinchillas. All species in this group are herbivorous, mainly eating plant leaves. Many species in this group are widely eaten by humans, including capybaras, spiny rats, guinea pigs, pacas, and agoutis.
Tanya Dewey (author), Animal Diversity Web.