The guinea pig or domestic guinea pig, also known as the cavy or domestic cavy, is a species of rodent belonging to the genus Cavia in the family Caviidae. Breeders tend to use the word cavy to describe the animal, while in scientific and laboratory contexts, it is far more commonly referred to by the common name guinea pig. Despite their common name, guinea pigs are not native to Guinea, nor are they closely related biologically to pigs, and the origin of the name is still unclear. They originated in the Andes of South America. Studies based on biochemistry and hybridization suggest they are domesticated animals that do not exist naturally in the wild, descendants of a closely related cavy species such as C. tschudii. They were originally domesticated as livestock for a source of meat, and are still consumed in some parts of the world.
Caviidae, the cavy family, is composed of rodents native to South America and includes the domestic guinea pig, wild cavies, and the largest living rodent, the capybara. They are found across South America in open areas from moist savanna to thorn forests or scrub desert. This family of rodents has fewer members than most other rodent families, with 19 species in 6 genera in 3 subfamilies.
The Vancouver Island marmot naturally occurs only in the high mountains of Vancouver Island, in British Columbia. This particular marmot species is large compared to some other marmots, and most other rodents. Marmots as a group are the largest members of the squirrel family, with weights of adults varying from 3 to 7 kg depending on age and time of year.
The genus Hydrochoerus contains two living and three extinct species of rodents from South America, the Caribbean island of Grenada, California and Panama. Capybaras are the largest living rodents in the world. The genus name is derived from the Greek ὕδωρ 'water' plus χοίρος 'pig'.
Caviomorpha is the rodent infraorder or 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, the extinct Josephoartigasia monesi 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 octodonts.
The term Hystricomorpha has had many definitions throughout its history. In the broadest sense, it refers to any rodent with a hystricomorphous zygomasseteric system. This includes the Hystricognathi, Ctenodactylidae, Anomaluridae, and Pedetidae. Molecular and morphological results suggest the inclusion of the Anomaluridae and Pedetidae in Hystricomorpha may be suspect. Based on Carleton & Musser 2005, these two families are discussed here as representing a distinct suborder Anomaluromorpha.
Caviinae is a subfamily uniting all living members of the family Caviidae with the exception of the maras, capybaras, and Kerodon. The subfamily traditionally contained the guinea pig or cavy-like forms along with the cursorially adapted (running) Kerodon. Molecular results suggest the Caviinae as so defined would be paraphyletic and Kerodon is more closely related to maras and capybaras than to other caviines. This led Woods and Kilpatrick (2005) to unite Kerodon and capybaras into the subfamily Hydrochoerinae within the Caviidae. These studies also suggest Microcavia and Cavia are more closely related to one another than either is to Galea.
The genus Kerodon contains two species of South American rock cavies, related to capybaras and guinea pigs. They are found in semiarid regions of northeast Brazil known as the Caatinga. This area has a rocky terrain with large granite boulders that contain rifts and hollows where Kerodon species primarily live.
Cavia is a genus in the subfamily Caviinae that contains the rodents commonly known as guinea pigs or cavies. The best-known species in this genus is the domestic guinea pig, Cavia porcellus, a meat animal in South America and a common household pet outside of that continent.
Santa Catarina's guinea pig or Moleques do Sul cavy is a rare guinea pig species of southeastern South America.
Proechimys is a genus of South American spiny rats of the family Echimyidae. All species of the genus are terrestrial. In the lowland Neotropical forests, Proechimys rodents are often the most abundant non-volant mammals. They are recognizable by reason of their elongated heads and long rostra, large and erect ears, narrow and long hind feet, and tails always shorter than head-and-body lengths. The dorsal pelage comprises a mixture of expanded, varyingly stiffened spines — hence the vernacular name of spiny rats — and soft hairs.
The montane guinea pig is a species of caviid rodent found in the Andes in South America. The montane guinea pig is the likely main ancestor of Cavia porcellus, the domestic cavy or domestic guinea pig, which appears to be a hybrid that includes lesser genetic contributions from other Cavia species.
Cavia anolaimae is a guinea pig species from South America. It is found in Colombia near Bogotá. It is believed to be a feral offshoot of the domestic guinea pig, Cavia porcellus, and is often treated as a synonym of C. porcellus, but Zúñiga et al. (2002), based on morphologic characters, recognized them as different species. According to the molecular analysis of Dunnum and Salazar (2010) C. anolaimae is a subspecies of Cavia aperea, C. aperea anolaimae, and a possible synonymous of C. a. guianae.
Euryzygomatomys is a genus of South American rodents, commonly called guiaras, in the family Echimyidae. It contains two extant and one fossil species, found in Argentina, Brazil and Paraguay. They are as follows:
The common yellow-toothed cavy is a species of rodent in the family Caviidae, closely related to the domesticated guinea pig. It is found in Argentina, Bolivia, Chile, and Peru. Its karyotype has 2n = 68 and FN = 136. G. musteloides is the most common and widely found member of Galea, and is present at elevations ranging from 20 to 5000 m above sea level. It has yellow teeth.
Thrichomys is a genus of South American rodents in the family Echimyidae. It contains at least five species, found in Bolivia, Brazil and Paraguay. They are as follows:
Galea is a genus of South American rodents of the family Caviidae. 5-6 extant species are known, found in Argentina, Bolivia, Chile, Peru and Brazil. They are:
Rhabdomys dilectus, the mesic four-striped grass rat, is a species of rodent in the family Muridae.
James Lloyd Patton, is an American evolutionary biologist and mammalogist. He is emeritus professor of integrative biology and curator of mammals at the Museum of Vertebrate Zoology, UC Berkeley and has made extensive contributions to the systematics and biogeography of several vertebrate taxa, especially small mammals.
Echimyidae is the family of neotropical spiny rats and their fossil relatives. This is the most species-rich family of hystricognath rodents. It is probably also the most ecologically diverse, with members ranging from fully arboreal to terrestrial to fossorial to semiaquatic habits. They presently exist mainly in South America; three members of the family also range into Central America, and the hutias are found in the Greater Antilles in the Caribbean. Species of the extinct subfamily Heteropsomyinae formerly lived on Cuba, Hispaniola, and Puerto Rico in the Antilles, probably until the arrival of Europeans.
