Hystricognathi

Porcupines are large rodents with coats of sharp spines, or quills, that protect them against predators. The term covers two families of animals, the Old World porcupines in the family Hystricidae, and the New World porcupines in the family Erethizontidae. Both families display superficially similar coats of rigid or semirigid quills, which are modified hairs composed of keratin, and belong to the infraorder Hystricognathi within the diverse order Rodentia. The two groups are distinct and are not closely related to each other within the Hystricognathi. The largest species of porcupine is the t

The pacarana (Dinomys branickii) is a rare and slow-moving hystricognath rodent indigenous to South America. Native Tupi people call it the pacarana (false paca) because it is superficially similar to the paca, a different rodent which is not in the same family. The pacarana has a chunky body and is large for a rodent, weighing up to and measuring up to in length, not including the thick, furry tail.

species of mammal

The Hystricognathi are an infraorder of rodents, distinguished from other rodents by the bone structure of their skulls. The masseter medialis (a jaw muscle) passes partially through a hole below each eye socket (called the infraorbital foramen) and connects to the bone on the opposite side. This, together with their lack of an infraorbital plate and the relative size of the infraorbital foramen, distinguishes hystricognaths from other rodent groups. The infraorder's name comes from Ancient Greek ὕστριξ (hústrix), meaning "porcupine", and γνάθος (gnáthos), meaning "jaw".

species of mammal

Caviomorpha is the rodent parvorder that unites all New World hystricognaths. It is supported by both fossil and molecular evidence. The Caviomorpha was for a time considered to be a separate order outside the Rodentia, but is now accepted as a genuine part of the rodents. Caviomorphs include the extinct Heptaxodontidae (giant hutias), the extinct Josephoartigasia monesi (the largest rodent ever known) and extant families of chinchilla rats, hutias, guinea pigs and the capybara, chinchillas and viscachas, tuco-tucos, agoutis, pacas, pacaranas, spiny rats, New World porcupines, coypu and octodo

The rodent parvorder or infraorder Phiomorpha comprises several living and extinct families found wholly or largely in Africa. Along with Anomaluromorpha and perhaps the extinct Zegdoumyidae, it represents one of the few early colonizations of Africa by rodents.

species of mammal