The Guinea pig is the best known representative of the family Cavidae but what is the relationship between guinea pigs and the animal kingdom?
The guinea pigs is known as a rodent and a member of the animal kingdom. But how do they link up with other members of the animal kingdom and what is their place in the whole structure of life?
This is quite a detailed post which looks to investigate this fascinating matter.
We will be working backwards from the domestic guinea pig and up the order and will link it with other species it comes into contact with.
An introduction to the animal kingdom
The Animal kingdom is the structure that encompasses organisms that have breath. In fact the 
word animal comes from the Latin word animalis which means ‘to have breath’. This means that creatures as diverse as humans, jellyfish, sponges, sharks, and giraffes are all encompassed in the same kingdom.
From there they are sub divided into sections in what is known as a taxonomic rank, by scientists called taxonomists. They group together species by physical characteristics. This is what puts us as humans together in the same family as apes as we share similar characteristics.
This is how all species of breath giving animals are ordered together, starting with the humble domestic guinea pig.
Guinea Pigs and the Animal Kingdom
The scientific name for the domestic guinea pig is Cavia porcellus but it is affectionately known as a cavy by guinea pig enthusiasts.
They belong to the genus Cavia, which is the grouping which pulls together all the related species to the guinea pig (kind of like its cousins). These species are the following;
Genus Cavia
Cavia anolaimae (often considered a synonym of C. porcellus) – Colombia
Cavia aperea – Brazilian guinea pig, widespread east of the Andes
Cavia fulgida – shiny guinea pig, eastern Brazil
Cavia guianae (often considered a synonym of C. porcellus) – Venezuela, Guyana, Brazil
Cavia intermedia – intermediate guinea pig, Moleques do Sul islands, Santa Catarina, Brazil, first described in 1999
Cavia magna – greater guinea pig, Uruguay, southeast Brazil
Cavia nana (often considered a synonym of C. tschudii)
Cavia porcellus – domestic guinea pig, wild ancestor unknown
Cavia tschudii – montane guinea pig, Peru south to northern Chile and northwest Argentina
source wikipedia
The genus Cavia is part of the sub family Caviinae which is in turn part of the family Caviidae. The sub family Caviinae unites all living members of the family Caviidae except for Kerodon, Capybaras and Maras.
Subfamily – Caviinae
Above the genus Cavia is part of the sub-family Caviinae. The following species are also part of this sub-family.
Galea – yellow-toothed cavies
Galea flavidens – Brandt’s yellow-toothed cavy (may be an invalid species)
Galea monasteriensis – Muenster yellow-toothed cavy
Galea musteloides – common yellow-toothed cavy
Galea spixii – Spix’s yellow-toothed cavy
Microcavia – mountain cavies
Microcavia australis – southern mountain cavy
Microcavia niata – Andean mountain cavy
Microcavia shiptoni – Shipton’s mountain cavy
Cavia – guinea pigs
Cavia aperea – Brazilian guinea pig
Cavia fulgida – shiny guinea pig
Cavia intermedia – intermediate guinea pig
Cavia magna – greater guinea pig
Cavia porcellus – domestic guinea pig
Cavia tschudii – montane guinea pig
Extinct species
– †Neoprocavia
– †Allocavia
– †Palaeocavia
– †Neocavia
– †Dolicavia
– †Macrocavia
– †Caviops
– †Pascualia
source wikipedia
The family Caviidae
The sub-family Caviinae is part of the family Caviidae which is the smallest of all the familes in the family Rodentia. Al it’s species are native to South America.
They are characterised by an appearance like a rabbit, large heads, and short, heavy bodies. They are herbivores and are keen on grasses and plant life.
Subfamily Caviinae: Guinea pigs (cavies)
Genus Cavia, this genus is especially called ‘cavy’.
Genus Galea
Genus Microcavia: Mountain cavies
Subfamily Dolichotinae
Genus Dolichotis: Patagonian hares, or maras
Subfamily Hydrochoerinae
Genus Hydrochoerus: Capybara
Genus Kerodon: Rock cavy
source wikipedia
The Infraorder Caviomorpha
The family Caviidae is part of the Caviomorpha which is a rodent infraorder or parvorder which happens to unite all the South American hystricognaths. It is supported by both fossil and molecular evidence.
This rodent infraorder is what unites guinea pigs with species such as chinchilla rats and spiny rats.
Infraorder Caviomorpha – New World hystricognaths
†Luribayomys – incertae sedis
Superfamily Erethizontoidea
Family Erethizontidae – New World porcupines
Superfamily Cavioidea
†Guiomys
†Scotamys
Dasyproctidae – agoutis and acouchis
Cuniculidae – pacas
†Eocardiidae
Dinomyidae – pacarana
Caviidae – cavies, capybaras, and maras
Superfamily Octodontoidea
†Caviocricetus – incertae sedis
†Dicolpomys – incertae sedis
†Morenella – incertae sedis
†Plateomys – incertae sedis
†Tainotherium Turvey, Grady & Rye, 2006 – incertae sedis
Octodontidae – degus and relatives
Ctenomyidae – tuco-tucos
Echimyidae – spiny rats
Myocastoridae – nutria
Capromyidae – hutias
†Heptaxodontidae – giant hutias (probably paraphyletic)
Superfamily Chinchilloidea
Chinchillidae – chinchillas and viscachas
†Neoepiblemidae
Abrocomidae – chinchilla rats
souce wikipedia
The Infraorder Hystricognathi
The cavimorpha are then part of The Hystricognathi which are an infraorder of rodents, that have a very similar bone structure in their skulls. Their masseuse medial is which is their jaw muscle passes in part through their infraorbital foramen and in turn connects to the bone on the other side to it. They also have no infraorbital plate but a similar sized infraorbital foramen. This sets them apart from other rodent groups.
Being part of the Hystricogathi is what unites guinea pigs with specie such as old and new world porcupines, cane eats and african mole rats.
Phiomorphan hystricognath families
Bathyergidae (African mole rats)
Hystricidae (Old World porcupines)
Petromuridae (dassie rat)
Thryonomyidae (cane rats)
Caviomorphan hystricognath families[edit]
Abrocomidae (chinchilla rats)
Capromyidae (hutias)
Caviidae (guinea pigs, wild cavies, and capybaras)
Chinchillidae (chinchillas, viscachas, and their fossil relatives)
Ctenomyidae (tuco-tucos)
Dasyproctidae (agoutis and acouchis)
Dinomyidae (pacaranas and their fossil relatives)
Echimyidae (spiny rats)
Erethizontidae (New World porcupines)
Myocastoridae (coypu)
Octodontidae (13 species including the degu)
source wikipedia
Within Hystricogathi there are 18 families which are then divided into two infraorders Phiomorpha and the Caviomorpha. The Caviomorpha mostly are native to South America and the Phiomorpha are from the Old words Europe, Africa, and Asia.
Hystricomorpha
The Hystricogathi are part of the Hystricomorpha and refers to any type of rodent (except dipodoids) with a hystricomorphous zygomasseteric system. They unite guinea pigs with rodents such as gundis and the Loatian rock rat.
Superfamily Ctenodactyloidea
Ctenodactylidae – gundis
†Tammquammyidae
Diatomyidae – Laotian rock rat
†Yuomyidae
†Chapattimyidae
Hystricognathiformes
†Tsaganomyidae
Hystricognathi – true hystricognaths
†”Baluchimyinae”
Hystricidae – Old World porcupines
Phiomorpha
†Myophiomyidae
†Diamantomyidae
†Phiomyidae
†Kenyamyidae
Petromuridae – dassie rat
Thryonomyidae – cane rats
Bathyergidae – blesmols
†Bathyergoididae
Caviomorpha – New World hystricognaths
Superfamily Erethizontoidea
Erethizontidae – New World porcupines
Superfamily Cavioidea
†Cephalomyidae
Dasyproctidae – agoutis and acouchis
Cuniculidae – pacas
†Eocardiidae
Dinomyidae – pacarana
Caviidae – cavies, capybaras, and guinea pigs
Superfamily Octodontoidea
Octodontidae – degus and relatives
Ctenomyidae – tuco-tucos
Echimyidae – spiny rats
Myocastoridae – nutria
Capromyidae – hutias
†Heptaxodontidae – giant hutias
Superfamily Chinchilloidea
Chinchillidae – chinchillas and viscachas
†Neoepiblemidae
Abrocomidae – chinchilla rats
source wikipedia
The Order Rodentia
Hystricomorpha are then part of the order Rodentia. Rodents are characterised by those species that have incisors that grow continuously in the lower and upper jaws and need to be kept short by gnawing,
There are over 30 families in the order Rodentia
Order Rodentia (from Latin, rodere, to gnaw)
Suborder Anomaluromorpha
Family Anomaluridae: scaly-tailed squirrels
Family Pedetidae: springhares
Suborder Castorimorpha
Superfamily Castoroidea
Family Castoridae: beavers
Superfamily Geomyoidea
Family Geomyidae: pocket gophers (true gophers)
Family Heteromyidae: kangaroo rats and kangaroo mice
Suborder Hystricomorpha
Family incertae sedis Diatomyidae: Laotian rock rat
Infraorder Ctenodactylomorphi
Family Ctenodactylidae: gundis
Infraorder Hystricognathi
Family Bathyergidae: African mole rats
Family Hystricidae: Old World porcupines
Family Petromuridae: dassie rat
Family Thryonomyidae: cane rats
Parvorder Caviomorpha
Family †Heptaxodontidae: giant hutias
Family Abrocomidae: chinchilla rats
Family Capromyidae: hutias
Family Caviidae: cavies, including Guinea pigs and the capybara
Family Chinchillidae: chinchillas and viscachas
Family Ctenomyidae: tuco-tucos
Family Dasyproctidae: agoutis
Family Cuniculidae: pacas
Family Dinomyidae: pacaranas
Family Echimyidae: spiny rats
Family Erethizontidae: New World porcupines
Family Myocastoridae: nutria, coypu
Family Octodontidae: octodonts
Suborder Myomorpha
Superfamily Dipodoidea
Family Dipodidae: jerboas and jumping mice
Superfamily Muroidea
Family Calomyscidae: mouse-like hamsters
Family Cricetidae: hamsters, New World rats and mice, muskrats, voles
Family Muridae: true mice and rats, gerbils, spiny mice, crested rat
Family Nesomyidae: climbing mice, rock mice, white-tailed rat, Malagasy rats and mice
Family Platacanthomyidae: spiny dormice
Family Spalacidae: mole rats, bamboo rats, and zokors
Suborder Sciuromorpha
Family Aplodontiidae: mountain beaver
Family Gliridae (also Myoxidae, Muscardinidae): dormice
Family Sciuridae: squirrels, including chipmunks, prairie dogs, and marmots
source wikipedia
The Clade Glires
Rodentia is then part of Glires (Latin glīrēs, dormice) which is a clade sometimes ranked as a grandorder that consists of rodents and lagomorphs (rabbits, hares, and pikas). Some think that rabbits are rodents but they are linked through the Glires clade.
Glires is then part of Euarchontoglires (synonymous with Supraprimates) which is a clade (superorder) of mammals, the members which are living belong to five of the following types of group; rodents, lagomorphs, treeshrews, colugos and primates (including humans).
Class Mammalia
Eutheria is then part of Mammalia who are a clade of endothermic amniotes that are distinguished from reptiles and birds by the possession of hair, three middle ear bones, mammary glands in females, and a neocortex.
Subclass Prototheria: monotremes: echidnas and the platypus
Subclass Theriiformes: live-bearing mammals and their prehistoric relatives
Infraclass †Allotheria: multituberculates
Infraclass †Triconodonta: triconodonts
Infraclass Holotheria: modern live-bearing mammals and their prehistoric relatives
Superlegion †Kuehneotheria
Supercohort Theria: live-bearing mammals
Cohort Marsupialia: marsupials
Magnorder Australidelphia: Australian marsupials and the monito del monte
Magnorder Ameridelphia: New World marsupials.
Cohort Placentalia: placentals
Magnorder Xenarthra: xenarthrans
Magnorder Epitheria: epitheres
Superorder Anagalida: lagomorphs, rodents, and elephant shrews
Superorder Ferae: carnivorans, pangolins, †creodonts, and relatives
Superorder Lipotyphla: insectivorans
Superorder Archonta: bats, primates, colugos, and treeshrews
Superorder Ungulata: ungulates
Order Tubulidentata incertae sedis: aardvark
Mirorder Eparctocyona: †condylarths, whales, and artiodactyls (even-toed ungulates)
Mirorder †Meridiungulata: South American ungulates
Mirorder Altungulata: perissodactyls (odd-toed ungulates), elephants, manatees, and hyraxes
The Animal Kingdom
This finally links guinea pigs and humans together in the animal kingdom.
Euarchontoglires is then part of Boreoeutheria is a clade (magnorder) of placental mammals. They have a composition of Euarchontoglires (Supraprimates), most pawed carnivores, sister taxa Laurasiatheria (most hoofed mammals), and several other groups
It links guinea pigs with species such as whales and dolphins
Magnorder Boreoeutheria
Superorder Euarchontoglires (Supraprimates)
Clade Euarchonta
Order Scandentia: treeshrews (Southeast Asia)
Clade Primatomorpha
Order Dermoptera: flying lemurs or colugos (Southeast Asia)
Order Primates: lemurs, bushbabies, monkeys, apes (cosmopolitan)
Clade Glires
Order Lagomorpha: pikas, rabbits, hares (Eurasia, Africa, Americas)
Order Rodentia: rodents (cosmopolitan)
Superorder Laurasiatheria
Clade Eulipotyphla
Order Erinaceomorpha: hedgehogs and gymnures (Eurasia, Africa, extinct in North America)
Order Soricomorpha: moles, shrews, solenodons (Eurasia, Africa, North America, northern South America)
Clade Cetartiodactyla
Order Cetacea: whales, dolphins and porpoises (cosmopolitan in seas)
Order Artiodactyla: even-toed ungulates, including pigs, hippopotamus, camels, giraffe, deer, antelope, cattle, sheep, goats (cosmopolitan)
Order Chiroptera: bats (cosmopolitan)
Clade Zooamata
Order Perissodactyla: odd-toed ungulates, including horses, donkeys, zebras, tapirs, and rhinoceroses (cosmopolitan)
Clade Ferae
Order Pholidota: pangolins or scaly anteaters (Africa, South and Southeast Asia)
Order Carnivora: carnivorans (cosmopolitan)
source wikipedia
Boreoeutheria is then part of Placentalia, this is a group of mammals.
Most of all living mammals are what is called placental: Monotremata and the Marsupialia are the other two living mammal groups.
What distinguishes placentals from other mammals is that the fetus is nourished during gestation via a placenta while, however this is not often the case with mammals.
They reproduce sexually, and their young are carried in the mother until they are fully developed. Placental mammals are viviparous.
Placentals are divided into these major groups:
Boreoeutheria, e.g. badgers, rabbits, guinea pigs, dogs
Euarchontoglires, e.g. rats, monkeys, humans, hares, treeshrews
Laurasiatheria, e.g. cattle, whales, moles, bats, cats
Xenarthra, e.g. armadillos, anteaters
Afrotheria, e.g. elephants, hyraxes, manatees
Placentals are part of Eutheria. Eutheria is one of two mammalian clades which has extant members that diverged in the Early Cretaceous or maybe the Late Jurassic.
The other clade is the Metatheria. Metatheria includes marsupials, most of whom have their neonates in pouches.
What distinguishes Eutheria from metatherians, a group that includes modern marsupials, are:
They have an enlarged malleolus at the foot of the tibia, which is the larger of the two shin bones.
There is a joint that is between the first metatarsal bone and the entocuneiform bone in the foot which is then offset further back than the joint which is between the second metatarsal and middle cuneiform bones . It has been discovered that in metatherians these joints are level with each other.
source wikipedia
So that’s what links guinea pigs and the animal kingdom. If you got this far, then well done!
