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• Anatomy
• Behavior
• Phiomorphan Hystricognath Famili.c3.a6
• Caviomorphan Hystricognath Famili.c3.a6
• Photos
• Taxonomy
• Families
• References
• Sources
• Keep Exploring

Anatomy

Hystricognathi is an infraorder of rodents. Hystricognaths are distinguished from other rodents by the bone structure of their skulls. The masseter medialis (a jaw muscle) passes partially through 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.

There are 18 families within the Hystricognathi, divided into two infraorders, the Phiomorpha and the Caviomorpha. The Caviomorpha are mostly native to South America, with a few species in North America, while the Phiomorpha occur in the Old World.

Behavior

Play behavior has been observed in seven hystricognath families. The caviomorphs chase each other, play-wrestle, and gallop. The longer-legged species chase more often than the shorter-legged species. They also rotate their heads and body muscles as a form of play (Fagen 1981).

Phiomorphan Hystricognath Familiæ

• Bathyergidae
• Hystricidae
• Petromuridae
• Thryonomyidae

Caviomorphan Hystricognath Familiæ

• Abrocomidae
• Agoutidae
• Capromyidae
• Caviidae
• Chinchillidae
• Ctenomyidae
• Dasyproctidae
• Dinomyidae
• Echimyidae
• Erethizontidae
• Myocastoridae
• Octodontidae

Photos

Taxonomy

Families

Abrocomidae

Chinchilla rats are members of the family Abrocomidae. They resemble Chinchillas in appearance, with a similar soft fur and silvery-grey color, but have a body-structure more like a short-tailed rat. They are social, tunnel-dwelling animals, and live in the Andes Mountains of South America. They are probably herbivorous, although this is not clear. [more]

At least 9 species and subspecies belong to the Family Abrocomidae.

More info about the Family Abrocomidae may be found here.

Agoutidae

The Dasyproctidae are a family of large South American rodents, comprising the agoutis and acouchis. Their fur is a reddish or dark color above, with a paler underside. They are herbivorous, often feeding on ripe fruit that falls from trees. They live in burrows, and, like squirrels, will bury some of their food for later use. [more]

At least 72 species and subspecies belong to the Family Agoutidae.

More info about the Family Agoutidae may be found here.

Bathyergidae

The blesmols, also known as mole rats, or African mole-rats, are burrowing rodents of the family Bathyergidae. They represent a distinct evolution of a subterranean life among rodents much like the pocket gophers of North America, the tuco-tucos in South America, or the fossorial muroids. [more]

At least 54 species and subspecies belong to the Family Bathyergidae.

More info about the Family Bathyergidae may be found here.

Capromyidae

Hutias are moderately large cavy-like rodents that inhabit the Caribbean Islands. They range in size from 20 to 60 centimetres (8-24 inches), and can weigh up to 7 kilograms (15 pounds). 20 species of hutia have been identified, and half may be extinct. Among those that perished were the giant hutias. They resemble the nutria in some respects and the largest species weigh up to seven kilograms. Tails are present, varying from vestiges to prehensile. They have stout bodies and large heads. Most species are herbivorous, though some consume small animals. Instead of burrowing underground, they nest in trees or rock crevices. Only a few species are common, while others have become endangered. [more]

At least 48 species and subspecies belong to the Family Capromyidae.

More info about the Family Capromyidae may be found here.

Caviidae

The Cavy family (Caviidae) is a family of rodents native to South America, and including the domestic guinea pig, wild cavies, and the capybara, among other animals. They are found across the continent, in open areas from moist savanna to thorn forests or scrub desert. [more]

At least 59 species and subspecies belong to the Family Caviidae.

More info about the Family Caviidae may be found here.

Chinchillidae

The family Chinchillidae contains the chinchillas, viscachas, and their fossil relatives. They are restricted to southern and western South America, often in association with the Andes. They are large rodents, weighing from 800 grams to 8 kilograms, with strong hind legs and large ears. All species have thick, soft fur, which is considered valuable in some species. [more]

At least 38 species and subspecies belong to the Family Chinchillidae.

More info about the Family Chinchillidae may be found here.

Dasyproctidae

The Dasyproctidae are a family of large South American rodents, comprising the agoutis and acouchis. Their fur is a reddish or dark color above, with a paler underside. They are herbivorous, often feeding on ripe fruit that falls from trees. They live in burrows, and, like squirrels, will bury some of their food for later use. [more]

At least 14 species and subspecies belong to the Family Dasyproctidae.

More info about the Family Dasyproctidae may be found here.

Dinomyidae

The family Dinomyidae was once a very successful group of South American hystricognath rodent, but now contains only a single living species, the Pacarana. The Dinomyidae included among its ranks the largest rodents known to date, the bison-sized Josephoartigasia monesi and the smaller Josephoartigasia magna. It is thought that the dinomyids were able to occupy ecological niches associated with large grazing mammals due to the lack of true ungulates in South America until its later connection to North America. The modern pacarana is only modest sized, considerably smaller than the capybara. [more]

At least 7 species and subspecies belong to the Family Dinomyidae.

More info about the Family Dinomyidae may be found here.

Echimyidae

The spiny rats are a group of hystricognath rodents in the family Echimyidae. They are distributed from central Central America through much of South America. They were also found in the West Indies until the 1800s. Some authorities consider the nutria from southern and central South America to be a part of this family. [more]

At least 198 species and subspecies belong to the Family Echimyidae.

More info about the Family Echimyidae may be found here.

Eocardiidae

At least 10 species and subspecies belong to the Family Eocardiidae.

More info about the Family Eocardiidae may be found here.

Erethizontidae

The New World porcupines, or Erethizontidae, are large arboreal rodents, distinguished by the spiny covering from which they take their name. They inhabit forests and wooded regions across North America, and into northern South America. Although both the New World and Old World porcupine families belong to the Hystricognathi branch of the vast order Rodentia, they are quite different and are not closely related. [more]

At least 62 species and subspecies belong to the Family Erethizontidae.

More info about the Family Erethizontidae may be found here.

Heptaxodontidae

The giant hutias are an extinct group of large rodents known from fossil and subfossil material in the West Indies. One species, Amblyrhiza inundata, is estimated to have weighed between 50 and 200 kg, big specimens being as large as an American Black Bear. This is much larger than Capybara, the largest rodent living today, but still much smaller than Phoberomys pattersoni and Phoberomys insolita, the largest rodents presently known. These animals may have persisted into historic times and were probably used as a food source by aboriginal humans. All giant hutias are in a single family Heptaxodontidae, which contains no living species. [more]

At least 5 species and subspecies belong to the Family Heptaxodontidae.

More info about the Family Heptaxodontidae may be found here.

Hydrochoeridae

At least 13 species and subspecies belong to the Family Hydrochoeridae.

More info about the Family Hydrochoeridae may be found here.

Hystricidae

The Old World porcupines, or Hystricidae, are large terrestrial rodents, distinguished by the spiny covering from which they take their name. They range over the south of Europe, most of Africa, India, and the Malay Archipelago as far east as Borneo. Although both the Old World and New World porcupine families belong to the Hystricognathi branch of the vast order Rodentia, they are quite different and are not closely related. [more]

At least 63 species and subspecies belong to the Family Hystricidae.

More info about the Family Hystricidae may be found here.

Octodontidae

The Octodontidae are a family rodents, restricted to south-western South America. Thirteen species of octodontid are recognised, arranged in nine genera. The best known species is the Degu, Octodon degus. [more]

At least 106 species and subspecies belong to the Family Octodontidae.

More info about the Family Octodontidae may be found here.

Petromuridae

The Dassie Rat, Petromus typicus, is an African rodent found among rocky outcroppings. It is the only living member of its genus, Petromus, and family, Petromuridae. The name "dassie" means "hyrax" in Afrikaans, and the two animals are found in similar habitats. Petromus means "rock mouse" and dassie rats are one of many rodents that are sometimes called rock rats. The family and genus names are sometimes misspelled as Petromyidae and Petromys. [more]

More info about the Family Petromuridae may be found here.

Thryonomyidae

The genus Thryonomys, also know as cane rats, grass cutters, or cutting grass, is a genus of rodent found throughout Africa south of the Sahara, the only members of the family Thyronomyidae. They are eaten in some African countries and are a pest species on many crops. [more]

At least 26 species and subspecies belong to the Family Thryonomyidae.

More info about the Family Thryonomyidae may be found here.

References

• Sciurognathi
• Hystricomorpha

Sources

• The text on this page is licensed under the GNU Free Documentation License. It includes material from Wikipedia retrieved Monday, May 26, 2008.
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