? Hystricomorpha Fossil Range: Eocene - Recent
Laotian Rock Rat drawing by R.J. Timmins
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Rodentia Suborder: Hystricomorpha
Families
Ctenodactylidae †Tammquammyidae †Diatomyidae †Yuomyidae †Chapattimyidae †Tsaganomyidae Laonastidae †"Baluchimyinae" Hystricidae †Myophiomyidae †Diamantomyidae †Phiomyidae †Kenyamyidae Petromuridae Thryonomyidae Bathyergidae †Bathyergoididae Erethizontidae Dasyproctidae Agoutidae †Eocardiidae Dinomyidae Caviidae Hydrochaeridae Octodontidae Ctenomyidae Echimyidae Myocastoridae Capromyidae †Heptaxodontidae Chinchillidae †Neoepiblemidae Abrocomidae The Eocene epoch (56-34 MYA) is a major division of the geologic timescale and the second epoch of the Palaeogene period in the Cenozoic era. ... Laotian Rock Rat (Laonastes aenigmamus) http://www. ... Binomial name Laonastes aenigmamus (Jenkins, Kilpatrick, Robinson, Timmins, 2005) The kha-nyou or Laotian rock rat (Laonastes aenigmamus) is a rodent from the Khammouan region of Laos. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria (coral, jellyfish, anenomes) Placozoa (trichoplax) Subregnum Bilateria (bilateral symmetry) Acoelomorpha (basal) Orthonectida (flatworms, echinoderms, etc. ... Typical Classes Subphylum Urochordata - Tunicates Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Eutheria (includes extinct ancestors)/Placentalia (excludes extinct ancestors) Afrosoricida Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata (extinct) Perissodactyla Pholidota Plesiadapiformes... Families Many, see text The order Rodentia is the most numerous of all the branches on the mammal family tree. ... Genera Ctenodactylus Felovia Massoutiera Pectinator Gundis (family Ctenodactylidae) are a group of small, stocky rodents found in Africa. ... Laotian Rock Rat - Wikipedia /**/ @import /skins/monobook/IE50Fixes. ... Genera  Atherurus  Hystrix  Thecurus  Trichys The Old World porcupines are large representatives of the terrestrial rodent mammals, distinguished by their spiny covering from which they take their name. ... Binomial name Petromus typicus , The Dassie Rat, Petromus typicus, is an African rodent found among rocky outcroppings. ... Species Thryonomys gregorianus (Lesser Cane Rat) Thryonomys swinderianus (Greater Cane Rat) The genus Thryonomys, also know as cane rats, is a genus of rodent found in Africa south of the Sahara. ... Genera Georychus Cryptomys Heliophobius Bathyergus Heterocephalus The blesmols, also known as mole rats, or African mole-rats, are burrowing rodents of the family Bathyergidae. ... Genera  Coendou  Sphiggurus  Erethizon  Echinoprocta The New World porcupines are large terrestrial rodents, distinguished by their spiny covering from which they take their name. ... Genera Dasyprocta Myoprocta Agouti The Dasyproctidae are a family of South American rodents, comprising three genera. ... Genera Dasyprocta Myoprocta Agouti The Dasyproctidae are a family of South American rodents, comprising three genera. ... The pacarana (Dinomys branickii) is a rare and slow-moving South American rodent found only in tropical forests of the western Amazon River basin and adjacent foothills of the Andes Mountains from northwestern Venezuela and Colombia to western Bolivia. ... Subfamilies  Caviinae  Dolichotinae The Cavy (family Caviidae) is divided in two subfamilies: Subfamily Caviinae: cavies and guinea pigs Genus Cavia, this genus is especially called cavy. ... Binomial name Hydrochoerus hydrochaeris (Linnaeus, 1766) The capybara (Hydrochoerus hydrochaeris) is the largest of living rodents (the long extinct rodent Phoberomys pattersoni was significantly bigger. ... Genera  Octodon  Octodontomys  Octomys  Spalacopus  Aconaemys  Pipanacoctomys  Salinoctomys  Tympanoctomys The Octodontidae are a family of South American rodents. ... The tuco-tucos are members of a group of rodents that belong to the family Ctenomyidae. ... Genera †Cercomys †Maruchito †Paulacoutomys †Willidewu †Adelphomys †Deseadomys †Paradelphomys †Stichomys †Xylechimys Dactylomys Kannabateomys Olallamys †Boromys †Brotomys †Heteropsomys †Puertoricomys †Acarechimys †Chasichimys †Eumysops Lonchothrix Mesomys †Palaeoechimys †Pampamys †Pattersomys †Protacaremys †Protadelphomys †Sallamys Proechimys Thrichomys Trinomys Carterodon Clyomys Euryzygomatomys Callistomys Diplomys Echimys Isothrix Makalata Pattonomys Phyllomys Santamartamys The spiny rats are a group of hystricognath... Binomial name Myocastor coypus (Molina, 1782) The Coypu (Myocastor coypus) or Nutria is a large, crepuscular, semiaquatic rodent native to South America, but now also present in Europe, Asia, and North America. ... Hutias The Bahamas Hutia - Geocapromys ingrahami, is a herbivorouss rodent until recently only found on remote East Plana Cay. ... Genera Amblyrhiza Clidomys Elasmodontomys Quemsia The giant hutias are an extinct group of large rodents known from fossil and subfossil material in the West Indies. ... Genera  Chinchilla  Lagidium  Lagostomus Chinchillas and their relatives viscachas are small, nocturnal mammals native to the Andes mountains in South America and belonging to the family Chinchillidae. ... Species Abrocoma bennettii Abrocoma boliviensis Abrocoma cinerea Chinchilla Rats are members of the Abrocoma genus that resemble Chinchillas (to which they are closely related) in appearance but have a body-structure more like a rat. ...

Skull of a capybara showing the enlarged infraorbital canal present in most members of the Hystricomorpha. This condition is termed hystricomorphy.

The term Hystricomorpha has had many definitions throughout its history. In the broadest sense it refers to any rodent (except dipodoids) with a hystricomorphous zygomasseteric system. This includes the Hystricognathi, Ctenodactylidae, Anomaluridae, and Pedetidae. Molecular and morphological results suggest that the the inclusion of the Anomaluridae and Pedetidae in Hystricomorpha may be suspect. Based on Carleton and Musser (2005), these two families are treated here as representinga distinct suborder Anomaluromorpha. Binomial name Hydrochoerus hydrochaeris (Linnaeus, 1766) The capybara (Hydrochoerus hydrochaeris) is the largest of living rodents (the long extinct rodent Phoberomys pattersoni was significantly bigger. ... A type of rodent zygomasseteric system where the infraorbital foramen, which runs from the anterior part of the orbit to the outside of the rostrum, becomes very large. ... Hystricognathi is a subordo of the Rodentia. ... Genera Ctenodactylus Felovia Massoutiera Pectinator Gundis (family Ctenodactylidae) are a group of small, stocky rodents found in Africa. ... Genera Anomalurus, Idiurus, Zenkerella The Anomaluridae or scaly-tailed flying squirrels are a family of rodents found in central Africa. ... ...

The modern definition of Hystricomorpha also known as Entodacrya or Ctenohystrica is a taxonomic hypothesis uniting the gundis with the hystricognath rodents (Carleton and Musser, 2005). There is considerable morphological support for this relationship and strong molecular support. If true, this hypothesis renders the traditional view of Sciurognathi invalid as it becomes a paraphyletic group. Genera Ctenodactylus Felovia Massoutiera Pectinator Gundis (family Ctenodactylidae) are a group of small, stocky rodents found in Africa. ... Comparative anatomy is the study of similarities and differences in organisms. ... Molecular phylogeny is the use of a genes molecular characteristics to classify an organism and to place it on a map of evolutionary relationships known as the phylogenetic tree. ... Infraorders Anomaluromorpha Castorimorpha Ctenodactylomorpha Geomorpha Glirimorpha Myodonta Sciurida Sciurognathi is a suborder of rodents that includes squirrels, chipmunks, beavers, and many types of mice. ... Paraphyletic - Wikipedia /**/ @import /skins-1. ...

Families

The following list of families is based on the taxonomy of Marivaux et al. (2002; 2004) who subjected a number of early fossil rodents to parsimony analysis and recovered support for the Hystricomorpha or Entodacrya hypothesis. Their results rendered the suborder Sciuravida as defined by McKenna and Bell (1997) to be polyphyletic and invalid. The symbol "†" is used to indicate groups where no living members survive. Taxonomy (from Greek verb tassein = to classify and nomos = law, science, cf economy) may refer to: the science of classification (see alpha taxonomy) a classification Initially taxonomy was only the science of classifying living organisms, but later the word was applied in a wider sense, and may also refer to... This cladogram shows the relationship among various insect groups. ... In biology, a taxon is polyphyletic if it is descended from more than one root form (in Greek poly = many and phyletic = racial). ...

• Suborder Hystricomorpha
  • Ctenodactylidae - gundis
  • †Tammquammyidae
  • †Diatomyidae
  • †Yuomyidae
  • †Chapattimyidae
  • Hystricognathiformes
    • †Tsaganomyidae
    • Hystricognathi - true hystricognaths
      • Laonastidae - incertae sedis - Laotian Rock Rat
      • †"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
          • Dasyproctidae - agoutis and acouchis
          • Agoutidae - pacas
          • †Eocardiidae
          • Dinomyidae - pacarana
          • Caviidae - cavies
          • Hydrochaeridae - capybara
        • 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

Genera Ctenodactylus Felovia Massoutiera Pectinator Gundis (family Ctenodactylidae) are a group of small, stocky rodents found in Africa. ... Hystricognathi is a subordo of the Rodentia. ... Laotian Rock Rat - Wikipedia /**/ @import /skins/monobook/IE50Fixes. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Genera  Atherurus  Hystrix  Thecurus  Trichys The Old World porcupines are large representatives of the terrestrial rodent mammals, distinguished by their spiny covering from which they take their name. ... Families †Myophiomyidae †Diamantomyidae †Phiomyidae †Kenyamyidae Petromuridae Thryonomyidae Bathyergidae †Bathyergoididae The rodent infraorder Phiomorpha is comprised of several living and extinct families found wholly or largely in Africa. ... Binomial name Petromus typicus , The Dassie Rat, Petromus typicus, is an African rodent found among rocky outcroppings. ... Species Thryonomys gregorianus (Lesser Cane Rat) Thryonomys swinderianus (Greater Cane Rat) The genus Thryonomys, also know as cane rats, is a genus of rodent found in Africa south of the Sahara. ... Genera Georychus Cryptomys Heliophobius Bathyergus Heterocephalus The blesmols, also known as mole rats, or African mole-rats, are burrowing rodents of the family Bathyergidae. ... Caviomorpha is an infraorder of hystricognath rodents. ... Genera  Coendou  Sphiggurus  Erethizon  Echinoprocta The New World porcupines are large terrestrial rodents, distinguished by their spiny covering from which they take their name. ... Genera Dasyprocta Myoprocta Agouti The Dasyproctidae are a family of South American rodents, comprising three genera. ... Genera Dasyprocta Myoprocta Agouti The Dasyproctidae are a family of South American rodents, comprising three genera. ... The pacarana (Dinomys branickii) is a rare and slow-moving South American rodent found only in tropical forests of the western Amazon River basin and adjacent foothills of the Andes Mountains from northwestern Venezuela and Colombia to western Bolivia. ... Subfamilies  Caviinae  Dolichotinae The Cavy (family Caviidae) is divided in two subfamilies: Subfamily Caviinae: cavies and guinea pigs Genus Cavia, this genus is especially called cavy. ... Binomial name Hydrochoerus hydrochaeris (Linnaeus, 1766) The capybara (Hydrochoerus hydrochaeris) is the largest of living rodents (the long extinct rodent Phoberomys pattersoni was significantly bigger. ... Genera  Octodon  Octodontomys  Octomys  Spalacopus  Aconaemys  Pipanacoctomys  Salinoctomys  Tympanoctomys The Octodontidae are a family of South American rodents. ... The tuco-tucos are members of a group of rodents that belong to the family Ctenomyidae. ... Genera †Cercomys †Maruchito †Paulacoutomys †Willidewu †Adelphomys †Deseadomys †Paradelphomys †Stichomys †Xylechimys Dactylomys Kannabateomys Olallamys †Boromys †Brotomys †Heteropsomys †Puertoricomys †Acarechimys †Chasichimys †Eumysops Lonchothrix Mesomys †Palaeoechimys †Pampamys †Pattersomys †Protacaremys †Protadelphomys †Sallamys Proechimys Thrichomys Trinomys Carterodon Clyomys Euryzygomatomys Callistomys Diplomys Echimys Isothrix Makalata Pattonomys Phyllomys Santamartamys The spiny rats are a group of hystricognath... Binomial name Myocastor coypus (Molina, 1782) The Coypu (Myocastor coypus) or Nutria is a large, crepuscular, semiaquatic rodent native to South America, but now also present in Europe, Asia, and North America. ... Hutias The Bahamas Hutia - Geocapromys ingrahami, is a herbivorouss rodent until recently only found on remote East Plana Cay. ... Genera Amblyrhiza Clidomys Elasmodontomys Quemsia The giant hutias are an extinct group of large rodents known from fossil and subfossil material in the West Indies. ... Genera  Chinchilla  Lagidium  Lagostomus Chinchillas and their relatives viscachas are small, nocturnal mammals native to the Andes mountains in South America and belonging to the family Chinchillidae. ... Species Abrocoma bennettii Abrocoma boliviensis Abrocoma cinerea Chinchilla Rats are members of the Abrocoma genus that resemble Chinchillas (to which they are closely related) in appearance but have a body-structure more like a rat. ...

References

• Carleton, M. D. and G. G. Musser. 2005. Order Rodentia. Pp745-752 in Mammal Species of the World A Taxonomic and Geographic Reference (D. E. Wilson and D. M. Reeder eds.). Baltimore, Johns Hopkins University Press.
• Huchon, D. E. J. P. Douzery. 2001. From the Old World to the New World: A molecular chronicle of the phylogeny and biogeography of hystricognath rodents. Molecular Phylogenetics and Evolution, 20:238-251.
• Landry, S. O. J. 1999. A proposal for a new classification and nomenclature for the glires. Mitt. Mus. Nat. Kd. Berl. Zool. Reihe, 75:283-316.
• Marivaux, L., M. Vianey-Liaud, and J.-J. Jaeger. 2004. High-level phylogeny of early Tertiary rodents: dental evidence. Zoological Journal of the Linnean Society, 142:105-134.
• Marivaux, L. J. L. Welcomme, M. Vianey-Liaud, and J.J. Jaeger. 2002. The role of Asia in the origin and diversification of hystricognathous rodents. Zoologica Scripta, 31:225-239.
• McKenna, Malcolm C., and Bell, Susan K. 1997. Classification of Mammals Above the Species Level. Columbia University Press, New York, 631 pp. ISBN 0-231-11013-8