Mammal classification - wikipedia Mammal classification Over 70 % of mammal species are in the orders Rodentia ( blue ), Chiroptera ( red ), and primate ( yellow ) Rodentia Chiroptera Soricomorpha Primates Carnivora Artiodactyla Diprotodontia Lagomorpha Didelphimorphia Cetacea Dasyuromorphia Afrosoricida Erinaceomorpha Cingulata Peramelemorphia Scandentia Perissodactyla Macroscelidea Pilosa Monotremata Proboscidea Mammalia is a class of animal within the Phylum Chordata. Mammal classification has been through several iterations since Carl Linnaeus initially defined the class. No classification system is universally accepted ; McKenna & Bell ( 1997 ) and Wilson & Reader ( 2005 ) provide useful recent compendiums. Many earlier ideas from Linnaeus et al have been completely abandoned by modern taxonomists, among these are the idea that bats are related to birds or that humans represent a group outside of other living things. Competing ideas about the relationships of mammal orders do persist and are currently in development. Most significantly in recent years, cladistic thinking has led to an effort to ensure that all taxonomic designations represent monophyletic groups. The field has also seen a recent surge in interest and modification due to the results of molecular phylogenetics. George Gaylord Simpson 's classic `` Principles of Classification and a Classification of Mammals '' ( Simpson, 1945 ) taxonomy text laid out a systematics of mammal origins and relationships that was universally taught until the end of the 20th century. Since Simpson 's 1945 classification, the paleontological record has been recalibrated, and the intervening years have seen much debate and progress concerning the theoretical underpinnings of systematization itself, partly through the new concept of cladistics. Though field work gradually made Simpson 's classification outdated, it remained the closest thing to an official classification of mammals. See list of placental mammals and list of monotremes and marsupials for more detailed information on mammal genera and species. Contents 1 Molecular classification of placentals 1.1 Atlantogenata 1.1. 1 Afrotheria 1.1. 2 Xenarthra 1.2 Boreoeutheria 1.2. 1 Euarchontoglires 1.2. 2 Laurasiatheria 2 Standardized textbook classification 2.1 Subclass Prototheria 2.2 Subclass Theria 3 McKenna / Bell classification 3.1 Subclass Prototheria 3.2 Subclass Theriiformes 4 Luo, Kielan - Jaworowska, and Cifelli classification 5 Simplified classification for non-specialists 6 See also 7 References Molecular classification of placentals Molecular studies by molecular systematists, based on DNA analysis, in the early 21st century have revealed new relationships among mammal families. Classification systems based on molecular studies reveal three major groups or lineages of placental mammals - Afrotheria, Xenarthra, and Boreotheria - which diverged from early common ancestors in the Cretaceous. The relationships between these three lineages is contentious, and all three have been proposed as basal in different hypotheses. The first divergence was that of the Afrotheria 110 -- 100 million years ago ( mya ). The Afrotheria proceeded to evolve and diversify in the isolation of the African - Arabian continent. The Xenarthra, isolated in South America, diverged from the Boreoeutheria approximately 100 -- 95 mya. The Boreoeutheria split into the Laurasiatheria and Euarchontoglires between 95 and 85 mya ; both of these groups evolved on the northern continent of Laurasia. After tens of millions of years of relative isolation, Africa - Arabia collided with Eurasia, and the formation of the Isthmus of Panama linked South America and North America, facilitating the distribution of mammals seen today. With the exception of bats and murine rodents, no placental land mammals reached Australasia until the first human settlers arrived approximately 50,000 years ago. It should however be noted that these molecular results are still controversial mainly because they are not reflected by morphological data and thus not accepted by many systematists. It is also important to note that fossil taxa are not and, in most cases can not, be included. Although there are instances of DNA being recovered from prehistoric mammals such as the ground sloth Mylodon and Neanderthal humans, Homo neanderthalensis, fossils can generally only be incorporated in morphological analyses. The following taxonomy only includes living placentals ( infraclass Eutheria ) : Atlantogenata Afrotheria Clade Afroinsectiphilia Order Macroscelidea Family Macroscelididae : ( 17 species ), elephant shrews ( Africa ) Order Afrosoricida Family Tenrecidae : ( 30 species ), tenrecs ( Madagascar ) and otter - shrews ( West and Central Africa ) Family Chrysochloridae : ( 21 species ), golden moles ( Africa south of the Sahara ) Order Tubulidentata Family Orycteropodidae : ( 1 species ), aardvark ( Africa south of the Sahara ) Clade Paenungulata Order Proboscidea Family Elephantidae : ( 3 species ), elephants ( Africa, Southeast Asia ) Order Hyracoidea Family Procaviidae : ( 4 species ), hyraxes, dassies ( Africa, Arabia ) Order Sirenia Family Dugongidae : ( 1 species ), dugong ( East Africa, Red Sea, North Australia ) Family Trichechidae : ( 3 species ), manatees ( tropical Atlantic coasts and adjacent rivers ) Xenarthra Order Cingulata Family Chlamyphoridae : ( 14 species ), armadillos ( Neotropical ) Family Dasypodidae : ( 7 species ), armadillos ( Neotropical and Nearctic ) Order Pilosa Family Cyclopedidae : ( 1 species ), silky anteater ( Neotropical ) Family Myrmecophagidae : ( 3 species ), anteaters ( Neotropical ) Family Megalonychidae : ( 2 species ), two - toed sloths ( Neotropical ) Family Bradypodidae : ( 4 species ), three - toed sloths ( Neotropical ) Boreoeutheria Euarchontoglires Chirogaleus furcifer Aye aye Capuchin Arctic hare Aplodontia Superorder Euarchonta Order Scandentia Family Ptilocercidae ( 1 species ), pen - tailed treeshrews ( Southeast Asia ) Family Tupaiidae : ( 19 species ), treeshrews ( Southeast Asia ) Clade Primatomorpha Order Dermoptera Family Cynocephalidae : ( 2 species ), flying lemurs or colugos ( Southeast Asia ) Order Primates : lemurs, bushbabies, monkeys, apes ( cosmopolitan ). Family Cheirogaleidae : ( 32 species ), dwarf lemurs ( Madagascar ) Family Lemuridae : ( 22 species ), lemurs ( Madagascar ) Family Lepilemuridae : ( 26 species ), sportive lemurs ( Madagascar ) Family Indriidae : ( 19 species ), indri and sifakas ( Madagascar ) Family Daubentoniidae : ( 1 species ), aye - aye ( Madagascar area ) Family Lorisidae : ( 9 species ), lorises and potto ( Africa and Southeast Asia ) Family Galagidae : ( 19 species ), galagos ( Africa ) Family Tarsiidae : ( 9 species ), tarsiers ( Southeast Asia ) Family Callitrichidae : ( 41 species ), marmosets and tamarins ( South America ) Family Cebidae : ( 14 species ), New World monkeys ( South America ) Family Cercopithecidae : ( 137 species ), Old World monkeys ( Africa and Eurasia ) Family Hylobatidae : ( 14 species ), gibbons ( Southeast Asia ) Family Hominidae : ( 7 species ), great apes ( worldwide ) Superorder Glires Order Lagomorpha : pikas, rabbits, hares ( Eurasia, Africa, Americas ) Family Leporidae : ( 60 species ), rabbits and hares ( Eurasia, Africa, Americas ) Family Ochotonidae : ( 30 species ), pikas ( Holarctic ) Order Rodentia : rodents ( cosmopolitan ) Family Aplodontiidae : ( 1 species ) mountain beaver ( North America ) Family Sciuridae : squirrels, chipmunks, and marmots ( cosmopolitan except Australia ) Family Gliridae : dormice ( Africa, Eurasia ) Family Castoridae : ( 2 species ) beavers ( Holarctic ) Family Geomyidae : ( about 35 species ) pocket gophers ( North America ) Family Heteromyidae : ( about 59 species ) kangaroo rats ( North America ) Family Dipodidae : jerboas and jumping mice ( Africa, Eurasia, North America ) Family Platacanthomyidae : spiny dormouse ( Southeast Asia ) Family Spalacidae : zokors, root rats, blind mole rats ( Africa, Eurasia ) Family Calomyscidae : mouse - like hamsters ( Asia ) Family Nesomyidae : old endemic African muroids ( Africa, Madagascar ) Family Cricetidae : hamsters, voles, and New World rats and mice ( Holarctic, South America ) Family Muridae : Old World rats and mice and gerbils ( Africa, Eurasia, Australia ) Family Anomaluridae : scaly - tailed flying squirrels ( Africa ) Family Pedetidae : springhaas ( Africa ) Family Ctenodactylidae : gundis ( Africa, Asia ) Family Hystricidae : ( 11 Species ) Old World porcupines ( Africa, Asia ) Family Bathyergidae : African mole - rats ( Africa ) Family Petromuridae : ( 1 species ) rock dassies ( Africa ) Family Thryonomyidae : cane rats ( Africa ) Family Erethizontidae : ( 19 species ) New World porcupines ( New World ) Family Chinchillidae : chinchillas and viscachas ( South America ) Family Dinomyidae : pacarana ( South America ) Family Caviidae : ( 18 species ) cavies and capybara ( South America ) Family Dasyproctidae : agoutis and acouchis ( South America ) Family Cuniculidae : paca ( South America ) Family Ctenomyidae : tuco - tucos ( South America ) Family Octodontidae : degus ( South America ) Family Abrocomidae : chinchilla - rats ( South America ) Family Echimyidae : spiny rats ( South America ) Family Capromyidae : hutias ( South America ) Family Myocastoridae : nutrias ( South America ) Laurasiatheria Order Eulipotyphla Family Solenodontidae : solenodons ( Cuba, Hispaniola ) Family Soricidae : shrews ( Eurasia, Africa, North America to northern South America ) Family Talpidae : moles, shrew - moles, desmans ( Eurasia, North America ) Family Erinaceidae : hedgehogs, moonrats ( Eurasia, Africa ) Clade Ferungulata Cohort Cetartiodactyla : includes orders Artiodactyla and Cetacea Family Camelidae : camels ( South America, Asia ) Family Suidae : pigs ( Africa, Eurasia ) Pig and piglet Family Tayassuidae : peccaries ( New World ) Family Hippopotamidae : hippos ( Africa ) Family Balaenopteridae : rorquals and grey whales Family Balaenidae : right and bowhead whales Family Kogiidae : dwarf sperm whales Family Physeteridae : sperm whales Family Ziphiidae : beaked whales Family Platanistidae : river dolphins Family Delphinidae : dolphins Family Pontoporiidae : La Plata River dolphin Family Lipotidae : baiji Family Iniidae : Amazon River dolphin Family Monodontidae : beluga and narwhal Family Phocoenidae : porpoises Family Tragulidae : mouse - deer ( Africa, Asia ) Family Antilocapridae : pronghorn ( North America ) Family Giraffidae : giraffe and okapi ( Africa ) Giraffe Family Cervidae : deer ( Holarctic, South America ) Family Moschidae : musk deer ( Asia ) Muntjac deer Family Bovidae : cattle, antelope, sheep, etc. ( Africa, Holarctic ) Pair of Icelandic Sheep Clade Pegasoferae Order Chiroptera : bats ( cosmopolitan ) Family Pteropodidae : flying foxes ( Africa, Eurasia, Australia ) Family Rhinolophidae : Old World horseshoe and leaf - nosed bats ( Old World ) Family Emballonuridae : sac - winged bats ( southern continents ) Family Craseonycteridae : Kitti 's hog - nosed bat ( Thailand ) Family Rhinopomatidae : mouse - tailed bats ( Africa, Southeast Asia ) Family Nycteridae : slit - faced bats ( Africa, Southeast Asia ) Family Megadermatidae : false vampire bats ( Africa, Southeast Asia, Australia ) Family Phyllostomidae : leaf - nosed bats ( South America ) Family Mormoopidae : leaf - chinned bats ( South America ) Family Noctilionidae : fishing bats ( South America ) Family Mystacinidae : short - tailed bats ( New Zealand ) Family Molossidae : free - tailed bats ( cosmopolitan ) Family Myzopodidae : sucker - footed bats ( Madagascar ) Family Thyropteridae : sucker - footed bats ( South America ) Family Furipteridae : smoky bats ( South America ) Family Natalidae : funnel - eared bats ( South America ) Family Vespertilionidae : vesper bats ( cosmopolitan ) Order Perissodactyla : odd - toed ungulates Family Equidae : horses, zebras, donkeys ( Africa, West and Central Asia ) Family Tapiridae : tapirs ( Central and South America, Southeast Asia ) Family Rhinocerotidae : rhinoceroses ( Africa, Southeast Asia ) Clade Ferae Order Pholidota Family Manidae : pangolins, scaly anteaters ( Africa, South Asia ) Order Carnivora : carnivorans ( cosmopolitan ) Family Felidae : cats Family Viverridae : civets, Asiatic palm civets Family Herpestidae : mongooses Family Hyaenidae : hyaenas, aardwolf Family Canidae : dogs Family Ursidae : bears Family Otariidae : eared seals Family Odobenidae : walrus Family Phocidae : seals Family Ailuridae : red panda Family Mephitidae : skunks Family Mustelidae : weasels and relatives Family Procyonidae : ringtails, olingos, kinkajou, raccoons, coatis Standardized textbook classification A somewhat standardized classification system has been adopted by most current mammalogy classroom textbooks. The following taxonomy of extant and recently extinct mammals is taken from Vaughan et al. ( 2000 ). This approach emphasizes an initial split between egg - laying prototherians and live - bearing therians. The therians are further divided into the marsupial Metatheria and the `` placental '' Eutheria. No attempt is made in this classification to further distinguish among the orders within these subclasses and infraclasses. This system also makes no note of the position of entirely fossil groups. In this and later taxonomies, families are merely listed under the order to which they belong. More detailed relationships among families is presented in the article of each order. Subclass Prototheria Order Monotremata Family Tachyglossidae ( echidnas ) Family Ornithorhynchidae ( platypuses ) Subclass Theria Infraclass Metatheria ( marsupials and their nearest ancestors ) Order Didelphimorphia Family Didelphidae ( opossums, etc. ) Order Paucituberculata Family Caenolestidae ( shrew opossums ) Order Microbiotheria Family Microbiotheriidae ( monito del montes ) Order Dasyuromorphia ( most carnivorous marsupials ) Family Thylacinidae ( Tasmanian tigers ) Family Myrmecobiidae ( numbats ) Family Dasyuridae ( Tasmanian devils, quolls, dunnarts, planigale, etc. ) Order Peramelemorphia ( bandicoots, bilbies, etc. ) Family Peramelidae Family Peroryctidae Order Notoryctemorphia ( marsupial moles ) Family Notoryctidae Order Diprotodontia Family Phascolarctidae ( koalas ) Family Vombatidae ( wombats ) Family Phalangeridae ( brushtail possums and cuscuses ) Family Potoroidae ( bettongs, potoroos and rat kangaroos ) Family Macropodidae ( kangaroos, wallabies, etc. ) Family Burramyidae ( pygmy possums ) Family Pseudocheiridae ( ringtailed possums, etc. ) Family Petauridae ( striped possum, Leadbeater 's possum, yellow - bellied glider, sugar glider, mahogany glider and squirrel glider ) Family Tarsipedidae ( honey possum ) Family Acrobatidae ( feathertail glider and feather - tailed possum ) Infraclass Eutheria Order Xenarthra Family Bradypodidae Family Megalonychidae Family Dasypodidae Family Myrmecophagidae Order Insectivora Noctilio albiventris Acerodon celebensis Cynopterus brachyotis Epomophorus wahlbergi Epomophorus Hypsignathus monstrosus Family Solenodontidae Family Nesophontidae Family Tenrecidae Family Chrysochloridae Family Erinaceidae Family Soricidae Family Talpidae Order Scandentia Family Tupaiidae Order Dermoptera Family Cynocephalidae Order Chiroptera Family Pteropodidae Family Emballonuridae Family Craseonycteridae Family Rhinopomatidae Family Nycteridae Family Megadermatidae Family Rhinolophidae Family Phyllostomidae Family Mormoopidae Family Noctilionidae Family Mystacinidae Family Molossidae Family Myzopodidae Family Thyropteridae Family Furipteridae Family Natalidae Family Vespertilionidae Order Primates Family Daubentoniidae Family Lemuridae Family Lepilemuridae Family Galagidae Family Lorisidae Family Cheirogaleidae Family Indriidae Family Tarsiidae Family Cercopithecidae Family Hominidae Family Hylobatidae Family Callitrichidae Family Cebidae Order Carnivora Family Felidae Family Viverridae Family Herpestidae Family Hyaenidae Family Canidae Family Ursidae Family Otariidae Family Phocidae Family Odobenidae Family Mustelidae Family Procyonidae Order Cetacea Family Balaenopteridae Family Eschrichtiidae Family Balaenidae Family Neobalaenidae Family Physeteridae Family Ziphiidae Family Platanistidae Family Delphinidae Family Monodontidae Family Phocoenidae Order Sirenia Family Dugongidae Family Trichechidae Order Proboscidea Family Elephantidae Order Perissodactyla Family Equidae Family Tapiridae Family Rhinocerotidae Order Hyracoidea Family Procaviidae Order Tubulidentata Family Orycteropodidae Order Artiodactyla Family Suidae Family Tayassuidae Family Hippopotamidae Family Camelidae Family Tragulidae Family Giraffidae Family Moschidae Family Cervidae Family Antilocapridae Family Bovidae Order Pholidota Family Manidae Order Rodentia Family Aplodontiidae Family Sciuridae Family Castoridae Family Geomyidae Family Heteromyidae Family Dipodidae Family Muridae Family Anomaluridae Family Pedetidae Family Ctenodactylidae Family Myoxidae Family Bathyergidae Family Hystricidae Family Petromuridae Family Thryonomyidae Family Erethizontidae Family Chinchillidae Family Dinomyidae Family Caviidae Family Hydrochaeridae Family Dasyproctidae Family Agoutidae Family Ctenomyidae Family Octodontidae Family Abrocomidae Family Echimyidae Family Capromyidae Family Heptaxodontidae Family Myocastoridae Order Lagomorpha Family Ochotonidae Family Leporidae Order Macroscelidea Family Macroscelididae McKenna / Bell classification In 1997, the mammals were comprehensively revised by Malcolm C. McKenna and Susan K. Bell, which has resulted in the `` McKenna / Bell classification ''. McKenna and Bell, Classification of Mammals : Above the species level, ( McKenna & Bell, 1997 ) is a comprehensive work on the systematics, relationships, and occurrences of all mammal taxa, living and extinct, down through the rank of genus. The authors worked together as paleontologists at the American Museum of Natural History, New York. McKenna inherited the project from Simpson and, with Bell, constructed a completely updated hierarchical system, covering living and extinct taxa that reflects the historical genealogy of Mammalia. The McKenna / Bell hierarchical listing of all of the terms used for mammal groups above the species includes extinct mammals as well as modern groups, and introduces some fine distinctions such as legions and sublegions and ranks which fall between classes and orders that are likely to be glossed over by the layman. Click on the highlighted link for a table comparing the traditional and the new McKenna / Bell classifications of mammals. Extinct groups are represented by †. Subclass Prototheria ( monotremes ) Order Platypoda : platypuses Family Ornithorhynchidae : platypuses Order Tachyglossa : echidnas ( spiny anteaters ) Family Tachyglossidae : echidnas Subclass Theriiformes Infraclass † Allotheria Order † Multituberculata : multituberculates Family † Plagiaulacidae Family † Bolodontidae Family † Hahnodontidae Family † Albionbaataridae Family † Arginbaataridae Family † Kogaionidae Family † Sloanbaataridae Family † Cimolodontidae Family † Ptilodontidae Family † Cimolomyidae Family † Eucosmodontidae Family † Taeniolabididae Family † Ferugliotheriidae Family † Sudamericidae Family † Patagoniidae Family † Groeberiidae Infraclass † Triconodonta Family † Amphilestidae Family † Triconodontidae Infraclass Holotheria Family † Chronoperatidae Superlegion † Kuehneotheria Family † Kuehneotheriidae Family † Woutersiidae Superlegion Trechnotheria Legion † Symmetrodonta Family † Shuotheriidae Order † Amphidontoidea Family † Amphidontidae Order † Spalacotherioidea Family † Tinodontidae Family † Spalacotheriidae Family † Barbereniidae Legion Cladotheria Sublegion † Dryolestoidea Order † Dryolestida Family † Austrotriconodontidae Family † Dryolestidae Family † Paurodontidae Family † Donodontidae Family † Mesungulatidae Family † Reigitheriidae Family † Brandoniidae Order † Amphitheriida Family † Amphitheriidae Sublegion Zatheria Family † Arguitheriidae Family † Arguimuridae Family † Vincelestidae Infralegion † Peramura Family † Peramuridae Infralegion Tribosphenida Family † Necrolestidae Supercohort † Aegialodontia Family † Aegialodontidae Supercohort Theria : therian mammals Family † Pappotheriidae Family † Holoclemensiidae Family † Kermackiidae Family † Endotheriidae Family † Picopsidae Family † Potamotelsidae Family † Plicatodontidae Order † Deltatheroida Family † Deltatheridiidae Family † Deltatheroididae Order † Asiadelphia Family † Asiatheriidae Family † Stagodontidae Family † Pediomyidae Cohort Marsupialia : marsupials Family † Yingabalanaridae Magnorder Australidelphia Superorder Microbiotheria Family Microbiotheriidae : monito del monte Superorder Eometatheria Order † Yalkaparidontia Family † Yalkaparidontidae Order Notoryctemorphia : marsupial moles Family Notoryctidae : marsupial moles Grandorder Dasyuromorphia : marsupial carnivores Family † Thylacinidae : recently extinct Tasmanian tiger and relatives Family Dasyuridae : Tasmanian devil, quolls, etc. Family Myrmecobiidae : numbat Grandorder Syndactyli : syndactylous marsupials Order Peramelia : bandicoots Family Peramelidae Family Peroryctidae Order Diprotodontia Family † Palorchestidae Family † Wynardiidae Family † Thylacoleonidae Family Tarsipedidae : honey possum Family † Ilariidae Family † Diprotodontidae Family Vombatidae : wombats Family Phalangeridae : phalangers Family Burramyidae : pygmy possums Family Macropodidae : rat kangaroos, kangaroos and wallabies Family Petauridae : gliders Family † Ektopodontidae Family Phascolarctidae : koala Family † Pilkipildridae Family † Miralinidae Family Acrobatidae : feather - tail glider, pen - tailed phalanger Magnorder Ameridelphia Order Didelphimorphia : opossums Family Didelphidae : opossums Family † Sparassocynidae Order Paucituberculata Family † Sternbergiidae Family Caenolestidae : rat or shrew opossums Family † Paleothentidae Family † Abderitidae Family † Sillustaniidae Family † Polydolopidae Family † Prepidolopidae Family † Bonapartheriidae Family † Argyrolagidae Family † Glasbiidae Family † Caroloameghiniidae Order † Sparassodonta Family † Mayulestidae Family † Hondadelphidae Family † Borhyaenidae Cohort Placentalia : placentals Order † Bibymalagasia Magnorder Xenarthra : edentates Order Cingulata : armadillos and relatives Family † Protobradidae Superfamily Dasypodoidea Family Dasypodidae : armadillos Family † Peltephilidae Superfamily † Glyptodontoidea Family † Pampatheriidae Family † Palaeopeltidae Family † Glyptodontidae : glyptodonts Order Pilosa : anteaters, sloths, and relatives Family † Entelopidae Suborder Vermilingua Family Myrmecophagidae : giant anteaters and relatives Family Cyclopedidae : pygmy anteater Suborder Phyllophaga Family † Rathymotheriidae Infraorder † Mylodonta Family † Scelidotheriidae Family † Mylodontidae Family † Orophodontidae Infraorder Megatheria Family † Megatheriidae : ground sloths Family Megalonychidae : two - toed sloths Family Bradypodidae : three - toed sloths Magnorder Epitheria : epitheres Superorder † Leptictida Family † Gypsonictopidae Family † Kulbeckiidae Family † Didymoconidae Family † Leptictidae Superorder Preptotheria Grandorder Anagalida Family † Zambdalestidae Family † Anagalidae Family † Pseudictopidae Mirorder Macroscelidea : elephant shrews Family Macroscelididae : elephant shrews Mirorder Duplicidentata Order † Mimotonida Family † Mimotonidae Order Lagomorpha Family Ochotonidae : pikas Family Leporidae : rabbits Mirorder Simplicidentata Order † Mixodontia Family † Eurymylidae Order Rodentia : rodents Family † Alagomyidae Family † Laredomyidae Suborder Sciuromorpha Family † Ischyromyidae Family † Allomyidae Family Aplodontiidae : mountain beaver Family † Mylagaulidae Infraorder † Theridomyomorpha Family † Theridomyidae Family † Reithroparamyidae Infraorder Sciurida Family Sciuridae : squirrels Family † Eutypomyidae Infraorder Castorimorpha Family Castoridae : beavers Family † Rhizospalacidae Suborder Myomorpha Family † Protoptychidae Infraorder Myodonta Family † Armintomyidae Family Dipodidae : jumping mice, jerboas Family † Simimyidae Family Muridae : rats, mice, and relatives Infraorder Glirimorpha Family Myoxidae : dormice Infraorder Geomorpha Family † Eomyidae Family † Florentiamyidae Family Geomyidae : pocket gophers, pocket mice, and kangaroo rats Suborder Anomaluromorpha Family † Parapedetidae Family Pedetidae : springhaas Family † Zegdoumyidae Family Anomaluridae : scaly - tailed squirrels Suborder Sciuravida Family † Ivanantoniidae Family † Sciuravidae Family † Chapattimyidae Family † Cylindrodontidae Family Ctenodactylidae : gundis Suborder Hystricognatha Family † Tsaganomyidae Infraorder Hystricognathi Family Hystricidae : Old World porcupines Family Erethizontidae : New World porcupines Family † Myophiomyidae Family † Diamantomyidae Family † Phiomyidae Family † Kenyamyidae Family Petromuridae : rock rats Family Thryonomyidae : cane rats Parvorder Bathyergomorphi Family Bathyergidae : mole - rats Family † Bathyergoididae Parvorder Caviida Family Agoutidae : agoutis and pacas Family † Eocardiidae Family Dinomyidae : pacarana Family Caviidae : cavies Family Hydrochoeridae : capybara Family Octodontidae : degus, tuco - tucos Family Echimyidae : spiny rats, nutria Family Capromyidae : hutias Family † Heptaxodontidae Family Chinchillidae : chinchillas, viscachas Family † Neoepiblemidae Family Abrocomidae : rat chinchillas Grandorder Ferae Order Cimolesta - pangolins and relatives Family † Palaeoryctidae Suborder † Didelphodonta Family † Cimolestidae Suborder † Apatotheria Family † Apatemyidae Suborder † Taeniodonta Family † Stylinodontidae Suborder † Tillodonta Family † Tillotheriidae Suborder † Pantodonta Family † Wangliidae Family † Harpyodidae Family † Bemalambdidae Family † Pastoralodontidae Family † Titanoideidae Family † Pantolambdidae Family † Barylambdidae Family † Cyriacotheriidae Family † Pantolambdodontidae Family † Coryphodontidae Suborder † Pantolesta Family † Pantolestidae Family † Paroxyclaenidae Family † Ptolemaiidae Suborder Pholidota Family † Epoicotheriidae Family † Metacheiromyidae Family Manidae : pangolins Suborder † Ernanodonta Family † Ernanodontidae Order † Creodonta : creodonts Family † Hyaenodontidae Family † Oxyaenidae Order Carnivora Suborder Feliformia Family † Viverravidae Family † Nimravidae Family Felidae : cats Family Viverridae : civets, Asiatic palm civets Family Herpestidae : mongooses Family Hyaenidae : hyaenas, aardwolf Family Nandiniidae : African palm civets Suborder Caniformia Family † Miacidae Infraorder Cynoidea Family Canidae : dogs Infraorder Arctoidea Parvorder Ursida Family † Amphicyonidae Family Ursidae : bears Family † Hemicyonidae Parvorder Pinnipedia Family Otariidae : eared seals Family Phocidae : seals, walrus Parvorder Mustelida Family Mustelidae : weasels, skunks, and relatives Family Procyonidae : ringtails, olingos, kinkajou, raccoons, coatis, red panda Grandorder Lipotyphla Family † Adapisoriculidae Order Chrysochloridea Family Chrysochloridae : golden moles Order Erinaceomorpha Family † Sespedectidae Family † Amphilemuridae Family † Adapisoricidae Family † Creotarsidae Family Erinaceidae : hedgehogs and relatives Family † Proscalopidae Family Talpidae : moles Family † Dimylidae Order Soricomorpha Family † Otlestidae Family † Geolabididae Family † Nesophontidae : recently extinct west Indian shrews Family † Micropternodontidae Family † Apternodontidae Family Solenodontidae : solenodons Family † Plesiosoricidae Family † Nyctitheriidae Family Soricidae : shrews Family Tenrecidae : tenrecs Grandorder Archonta Order Chiroptera : bats Family Pteropodidae : flying foxes Family † Archaeonycteridae Family † Paleochiropterygidae Family † Hassianycterididae Family Emballonuridae : sac - winged bats Family Rhinopomatidae : mouse - tailed bats Family Craseonycteridae : bumblebee bats Family Megadermatidae : false vampire bats Family Nycteridae : hispid bats Family Rhinolophidae : horseshoe and Old World leaf - nosed bats Family Mystacinidae : New Zealand short - tailed bats Family Noctilionidae : fishing bats Family Mormoopidae : spectacled bats Family Phyllostomidae : New World leaf - nosed and vampire bats Family † Philisidae Family Molossidae : free - tailed bats Family Natalidae : funnel - eared bats Family Furipteridae : smoky bats Family Thyropteridae : New World sucker - footed bats Family Myzopodidae : Old World sucker - footed bats Family Vespertilionidae : common bats Order Primates : primates Family † Purgatoriidae Family † Microsyopidae Family † Micromomyidae Family † Picromomyidae Family † Plesiadapidae Family † Palaechthonidae Family † Picrodontidae Family † Paramomyidae Family † Plagiomenidae Family † Mixodectidae Family Galeopithecidae : colugos Family † Plesiopithecidae Family Daubentoniidae : aye - aye Family † Adapidae Family Lemuridae : lemurs Family Lorisidae : lorises and galagos Family Cheirogaleidae : dwarf lemurs Family † Archaeolemuridae Family † Palaeopropithecidae Family Indriidae : indris and sifakas Family † Carpolestidae Family † Omomyidae Family † Microchoeridae Family † Afrotarsiidae Family Tarsiidae : tarsiers Family † Eosimiidae Family † Parapithecidae Family † Pliopithecidae Family Cercopithecidae : Old World monkeys including colobuses Family Hominidae : humans, greater apes, lesser apes Family Callitrichidae : marmosets Family Atelidae : New World monkeys Order Scandentia Family Tupaiidae : tree shrews Grandorder Ungulata : ungulates Order Tubulidentata Family Orycteropodidae : aardvark Order † Dinocerata Family † Uintatheriidae Mirorder Eparctocyona Order † Procreodi Family † Oxyclaenidae Family † Arctocyonidae Order † Condylarthra Family † Hyopsodontidae Family † Mioclaenidae Family † Phenacodontidae Family † Periptychidae Family † Peligrotheriidae Family † Didolodontidae Order † Arctostylopida Family † Arctostylopidae Order Cete : whales and relatives Family † Triisodontidae Family † Mesonychidae : mesonychids Family † Hapalodectidae Family † Basilosauridae Family † Protocetidae Family † Remingtonocetidae Family † Agorophiidae Family † Squalodontidae Family † Rhabdosteidae Family † Aetiocetidae Family † Mammalodontidae Family † Cetotheriidae Family Balaenopteridae : rorquals and grey whales Family Balaenidae : right and bowhead whales Family Physeteridae : sperm whales Family Hyperoodontidae : beaked whales Family Platanistidae : river dolphins Family Delphinidae : dolphins Family Pontoporiidae : La Plata River dolphin Family Lipotidae : baiiji Family Iniidae : Amazon River dolphin Family † Kentridontidae Family Monodontidae : beluga and narwhal Family † Odobenocetopsidae Family † Dalpiazinidae Family † Acrodelphinidae Family Phocoenidae : porpoises Family † Albireonidae Family † Hemisyntrachelidae Order Artiodactyla : even - toed ungulates Family † Raoellidae Family † Choeropotamidae Family Suidae : pigs Family Tayassuidae : peccaries Family † Santheriidae Family Hippopotamidae : hippos Family † Dichobunidae Family † Cebochoeridae Family † Mixtotheriidae Family † Helohyidae Family † Haplobunodontidae Family † Anthracotheriidae Family † Dacrytheriidae Family † Anoplotheriidae Family † Cainotheriidae Family † Agriochoeridae Family † Oreodontidae Family † Entelodontidae Family † Xiphodontidae Family Camelidae : camels and llamas Family † Oromerycidae Family † Protoceratidae Family † Amphimerycidae Family † Hypertragulidae Family Tragulidae : mouse deer Family † Leptomerycidae Family † Bachitheriidae Family † Lophiomerycidae Family † Gelocidae Family Moschidae : musk deer Family Antilocapridae : pronghorn Family † Palaeomerycidae Family † Hoplitomerycidae Family Cervidae : deer Family † Climacoceratidae Family Giraffidae : giraffe and okapi Family Bovidae : cattle, antelope, and relatives Mirorder † Meridiungulata Family † Perutheriidae Family † Amilnedwardsiidae Order † Litopterna Family † Protolipternidae Family † Macraucheniidae Family † Notonychopidae Family † Adianthidae Family † Proterotheriidae Order † Notoungulata : notoungulates Family † Henricosborniidae Family † Notostylopidae Family † Isotemnidae Family † Leontiniidae Family † Notohippidae Family † Toxodontidae Family † Homalodotheriidae Family † Archaeopithecidae Family † Oldfieldthomasiidae Family † Interatheriidae Family † Campanorcidae Family † Mesotheriidae Family † Archaeohyracidae Family † Hegetotheriidae Order † Astrapotheria Family † Eoastrapostylopidae Family † Trigonostylopidae Family † Astrapotheriidae Order † Xenungulata Family † Carodniidae Order † Pyrotheria Family † Pyrotheriidae Mirorder Altungulata Order Perissodactyla : odd - toed ungulates Family Equidae : horses Family † Palaeotheriidae Family † Brontotheriidae Family † Anchilophidae Family † Eomoropidae Family † Chalicotheriidae Family † Hyracodontidae Family Rhinocerotidae : rhinoceroses Family † Helaletidae Family † Isectolophidae Family † Lophiodontidae Family † Deperetellidae Family † Lophialetidae Family Tapiridae : tapirs Order Uranotheria : elephants, manatees, hyraxes, and relatives Family † Pliohyracidae Family Procaviidae : hyraxes Family † Phenacolophidae Family † Arsinoitheriidae Family † Prorastomidae Family Dugongidae : dugongs Family Trichechidae : manatees Family † Desmostylidae Family † Anthracobunidae Family † Moeritheriidae Family † Numidotheriidae Family † Barytheriidae Family † Deinotheriidae Family † Palaeomastodontidae Family † Phiomiidae Family † Hemimastodontidae Family † Mammutidae : mastodons and relatives Family † Gomphotheriidae : gomphotheres Family Elephantidae : modern elephants Luo, Kielan - Jaworowska, and Cifelli classification Several important fossil mammal discoveries have been made that have led researchers to question many of the relationships proposed by McKenna and Bell ( 1997 ). Additionally, researchers are subjecting taxonomic hypotheses to more rigorous cladistic analyses of early mammal fossils. Luo et al. ( 2002 ) summarized existing ideas and proposed new ideas of relationships among mammals at the most basal level. They argued that the term mammal should be defined based on characters ( especially the dentary - squamosal jaw articulation ) instead of a crown - based definition ( the group that contains most recent common ancestor of monotremes and therians and all of its descendants ). Their definition of Mammalia is roughly equal to the Mammaliaformes as defined by McKenna and Bell ( 1997 ) and other authors. They also define their taxonomic levels as clades and do not apply Linnean hierarchies. Mammalia † Sinoconodon - earliest and most basal of mammals Unnamed clade 1 - a clade that contains all other mammals. These are characterized by determinant growth and occlusal features of the cheek teeth. † Morganucodontidae - morganucodontids, including † Morganucodon, † Megazostrodon, and others † Docodonta - docodonts, including † Haldanodon and † Castorocauda ( Ji et al., 2006 ) Unnamed clade 2 - a clade containing all living mammals and some fossil relatives. It is characterized by the loss of a post dentary trough and a widened braincase. † Hadrocodium † Kuehneotherium Crown - group Mammalia - the group that contains most recent common ancestor of monotremes and therians and all of its descendants. This group is defined by additional characters relating the occlusion of molars and the presence of a well - developed masseteric fossa. Australosphenida - a clade that contains monotremes and their fossil relatives. These fossils include † Ambondro, † Asfaltomylos, † Ausktribosphenos, and † Bishops. If correct, this clade represents an independent evolution of the tribosphenic molar in southern continents. Trechnotheria - Therians, spalacotheriids and their relatives. They are characterized by features of the scapula, tibia, and humerus. † Spalacotheriidae - including Akidolestes, Zhangheotherium, and Maotherium. Cladotheria - Therians, dryolestids, and their relatives. They are characterized by features of the tribosphenic molar and the angular process of the dentary. † Dryolestidae † Amphitherium - incertae sedis ( it may be a prototribosphenidan ) Prototribosphenida - Therians and fossil relatives including † Vincelestes. Characterized by features of the cochlea including coiling. † Vincelestes Zatheria - Therians and fossil relatives including the `` peramurids ''. Characterized by the presence of wear in the talonid of the lower molars. † `` Peramuridae '' - † Peramus and relatives. Known only from preserved mandibles and distinctly zatherian molars. Boreosphenida - Therians and fossil relatives including † Kielantherium. They are characterized by molar features. † Kielantherium † Deltatheroida including † Deltatheridium - incertae sedis ( it may represent a metatherian ) Crown - group Theria - the group that contains most recent common ancestor of marsupials and placentals and all of its descendants. Characterized by a host of molar features, aspects of the alispenoid, and aspects of the astragalus region. † Eutriconodonta - incertae sedis. Triconodonts appear to be a member of the crown - Mammalia clade, but their relationships within it are unknown. It is also not certain that they represent a monophyletic group. Examples include Repenomamus. † Multituberculata - incertae sedis. Luo e al. ( 2002 ) argue that multituberculates can not be confidently placed in a particular clade of mammals. They suggest that they represent either basal mammals or are sister to the Trechnotheria. Simplified classification for non-specialists This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. ( January 2015 ) The following classification is a simplified version based on current understanding suitable for non-specialists who want to understand how living genera are related to each other. The classification ignores differences in levels and thus can not be used to estimate the respective distances between taxa. It also ignores taxa that became extinct in pre-historic times. Finally, English names are preferred whenever they exist. This makes it especially suited for non-specialists who wish to gain an easy overview. For the full picture, the non-simplified versions above should be consulted. Monotremes ( prototheria ) : echidnas and platypus Platypus Echidnas ( tachyglossids ) Live - bearing mammals ( theria ) Marsupials Opossums ( didelphids ) Shrew opossums ( caenolestids ) Australodelphia : Australian marsupials and monito del Monte Monito del Monte Dasyuromorphs Dasyurids : antechinuses, quolls, dunnarts, Tasmanian devil, and allies Numbat Peramelemorphs : bilbies and bandicoots Bilbies ( thylacomyids ) Bandicoots ( peramelids ) Marsupial moles ( notoryctids ) Diprotodonts Koala Wombats ( vombatids ) Phalangerids : brushtail possums and cuscuses Pygmy possums ( burramyids ) Honey possum Petaurids : striped and Leadbeater 's possums, and yellow - bellied, suger, mahogany and squirrel glider Ringtailed possums ( pseudocheirids ) Potorids : potoroos, rat kangaroos and bettongs Acrobatids : feathertail glider and feather - tailed possum Musky rat - kangaroo Macropodids : kangaroos, wallabies and allies Placentals Atlantic placentals ( atlantogenatans ) Afroplacentals ( afrotherians ) Afroinsectiphilians : elephant shrews, tenrecs, otter shrews, golden moles, and aardvark Elephant shrews ( macroscelidids ) Afrosoricids : tenrecs and golden moles Tenrecids : tenrecs and otter shrews Golden moles ( chrysochlorids ) Aardvark Paenungulates : hyraxes, elephants, dugongs and manatees Hyraxes or dassies ( procaviids ) Elephants ( elephantids ) Sirenians : dugong and manatees Dugong Manatees ( trichechids ) Xenarthrans Pilosans : sloths and anteaters Anteaters ( vermilinguans ) Silky anteater Myrmecophagids : giant anteater and tamanduas Sloths ( folivorans ) Three - toed sloths ( bradypodids ) Two - toed sloths ( megalonychids ) Armadillos ( dasypodids ) Northern placentals ( boreoeutherians ) Supraprimates ( euarchontoglires ) Euarchontans : treeshrews, colugos and primates Treeshrews ( scandentians ) Tupaiids : all treeshrews except pen - tailed Pen - tailed treeshrew Colugos or flying lemurs ( cynocephalids ) Primates Strepsirrhines : lemur - and loris - like primates Lemur - like primates ( lemuriforms ) Cheirogaleids : dwarf lemurs and mouse - lemurs Aye - aye True lemurs ( lemurids ) Sportive lemurs ( lepilemurids ) Indriids : woolly lemurs and allies Loris - like primates ( lorisiforms ) Lorisids : lorises, pottos and allies Galagos ( galagids ) Haplorhines : tarsiers, monkeys and apes Tarsiers ( tarsiids ) Anthropoid primates New World monkeys ( platyrrhines ) Callitrichids : marmosets and tamarins Cebids : capuchins and squirrel monkeys Aotids : night or owl monkeys Pitheciids : titis, sakis and uakaris Atelids : howler, spider, woolly spider, and woolly monkeys Catarrhines Old World monkeys ( cercopithecids ) Hominoid primates Gibbons ( hylobatids ) Great apes ( hominids ) : incl. Humans Glires : pikas, rabbits, hares, and rodents Lagomorphs : pikas, rabits and hares Leporids : rabbits and hares Pikas ( ochotonids ) Rodents Anomalure - like rodents ( anomaluromorphs ) : Scaly - tailed squirrels and springhares Scaly - tailed squirrels or anomalures ( anomalurids ) Springhares ( pedetids ) Beaver - like rodents ( castorimorphs ) Beavers ( castorids ) Gopher - like rodents ( geomyoid rodents ) Pocket or true gophers ( geomyids ) Heteromyids : kangaroo rats and kangaroo mice Porcupine - like rodents ( hystricomorphs ) Laotian rock rat Gundis ( ctenodactylids ) Hystricognaths African mole rats ( bathyergids ) Old World porcupines ( hystricids ) Dassie rat Cane rats ( thryonomyids ) Cavy - like rodents ( caviomorphs ) Chinchilla rats ( abrocomids ) Hutias ( capromyids ) Cavies ( caviids ) : incl. Guinea pigs and capybara Chinchillids : chinchillas and viscachas Tuco - tucos ( ctenomyids ) Agoutis ( dasyproctids ) Pacas ( cuniculids ) Pacarana Spiny rats ( echymyids ) New World porcupines ( erethizontids ) Myocastorids : nutria and coypu Octodonts ( octodontids ) : Andean rock - rats, degus and viscacha - rats Mouse - like rodents ( myomorphs ) Dipodids : jerboas and jumping mice Muroid rodents Mouse - like hamsters ( calomyscids ) Cricetids : hamsters, New World rats and mice, voles Murids : true mice and rats, gerbils, spiny mice, crested rat Nesomyids : climbing mice, rock mice, white - tailed rat, Malagasy rats and mice Spiny dormice ( platacanthomyids ) Spalacids : mole rats, bamboo rats, and zokors Squirrel - like rodents ( sciuromorphs ) Mountain beaver Dormice ( glirids ) Squirrels ( sciurids ) : incl. chipmunks, prairie dogs, and marmots Laurasian placentals ( laurasiatherians ) Hedgehogs ( erinaceids ) Soricomorphs : moles, shrews, solenodons Shrews ( soricids ) Moles ( talpids ) Solenodons ( solenodontids ) Ferungulates : ungulates, cetaceans, bats, pangolins and carnivorans Cetartiodactyls : camels, swine, cetaceans, hippos, and ruminants Camelids : camels and llamas Swine ( suinans ) : pigs and peccaries Pigs ( suids ) Peccaries ( tayassuids ) Cetruminantians : cetaceans hippos and ruminants Cetancodonts : Cetaceans and hippos Cetaceans : Whales, dolphins and porpoises Baleen whales ( mysticetes ) Balaenids : right whales and bowhead whale Rorquals ( balaenopterids ) Gray whale Pygmy right whale Toothed whales ( odontocetes ) Dolphins ( delphinids ) Monodontids : beluga and narwhal Beluga Narwhal Porpoises ( phocoenids ) Sperm whale Kogiids : pygmy and dwarf sperm whale River dolphins ( platanistoid whales ) Iniids : Amazon and Bolivian river dolphin La Plata dolphin Platanistids : Ganges and Indus river dolphins Beaked whales ( ziphids ) Hippos ( hippopotamids ) Ruminantiamorphs : chevrotains, pronghorn, giraffes, musk deer, deer, and bovids Chevrotains ( tragulids ) Pecorans Pronghorn Giraffids : giraffe and okapi Musk deer ( moschids ) Deer ( cervids ) Bovids : cattle, goats, sheep and antelope Pegasoferans : bats, odd - toed ungulates, pangolins and carnivorans Bats ( chiropterans ) Megabats ( pteropodids ) Microbats ( microchiropterans ) Sac - winged or sheath - tailed bats ( emballonurids ) Rhinopomatoid bats Mouse - tailed bats ( rhinopomatids ) Bumblebee bat or Kitti 's hog - nosed bat Rhinolophoid bats Horseshoe bats ( rhinolophids ) Hollow - faced or slit - faced bats ( nycterids ) False vampires ( megadermatids ) Vesper bats or evening bats ( vespertilionids ) Molossoid bats Free - tailed bats ( molossids ) Pallid bats ( antrozoids ) Nataloid bats Funnel - eared bats ( natalids ) Sucker - footed bats ( myzopodids ) Disc - winged bats ( thyropterids ) Smoky bats ( furipterids ) Noctilionoid bats Bulldog or fisherman bats ( noctilionids ) New Zealand short - tailed bats ( mystacinids ) Ghost - faced or moustached bats ( mormoopids ) Leaf - nosed bats ( phyllostomids ) Zooamatans : odd - toed ungulates, pangolins and carnivorans Odd - toed ungulates ( perissodactyls ) Horses ( equids ) Ceratomorphs Tapirs ( tapirids ) Rhinoceroses ( rhinocerotids ) Ferans Pangolins or scaly anteaters ( manids ) Carnivorans Cat - like carnivorans ( feliforms ) African palm civet Feloid carnivorans Asiatic linsangs ( prionodontids ) Cats ( felids ) Viverroid carnivorans Viverrids : civets and allies Herpestoid carnivorans Hyaenids : hyenas and aardwolf Malagasy carnivorans ( euplerids ) Herpestids : mongooses and allies Dog - like carnivorans ( caniforms ) Canids : dogs and allies Arctoid carnivorans Bears ( ursids ) Musteloid carnivorans Red panda Mephitids : skunks and stink badgers Mustelids : weasels, martens, badgers, wolverines, minks, ferrets and otters Procyonids : raccoons and allies Pinnipeds Walrus Otariids : sea lions, eared seals, fur seals True seals ( phocids ) See also Animal List of mammals List of prehistoric mammals Mammal References Jump up ^ Vaughan, Terry A. ; Ryan, James M. ; Czaplewski, Nicholas J. ( 2015 ), `` Chapter 4 : Classification of Mammals '', Mammalogy ( Sixth ed. ), ISBN 9781284032093 Jump up ^ Marks, Jonathan M. ( 1995 ). Human Biodiversity : Genes, Race, and History. ISBN 9780202366562. ^ Jump up to : Kriegs, Jan Ole ; Churakov, Gennady ; Kiefmann, Martin ; Jordan, Ursula ; Brosius, Jürgen ; Schmitz, Jürgen ( 2006 ). `` Retroposed Elements as Archives for the Evolutionary History of Placental Mammals ''. PLoS Biology. 4 ( 4 ) : e91. doi : 10.1371 / journal. pbio. 0040091. PMC 1395351. PMID 16515367. Jump up ^ Nishihara, H. ; Maruyama, S. ; Okada, N. ( 2009 ). `` Retroposon analysis and recent geological data suggest near - simultaneous divergence of the three superorders of mammals ''. Proceedings of the National Academy of Sciences. 106 ( 13 ) : 5235 -- 5240. doi : 10.1073 / pnas. 0809297106. PMC 2655268. PMID 19286970. The Wikibook Dichotomous Key has a page on the topic of : Mammalia Ji, Q. ; Luo, Z. - X. ; Yuan, C. - X. ; Tabrum, A.R. ( 2006 ). `` A swimming mammaliaform from the Middle Jurassic and ecomorphological diversification of early mammals ''. Science. 311 ( 5764 ) : 1123 -- 1127. doi : 10.1126 / science. 1123026. PMID 16497926. Luo, Z. - X. ; Kielan - Jaworowska, Z. ; Cifelli, R.L. ( 2002 ). `` In quest for a phylogeny of Mesozoic mammals ''. Acta Palaeontologica Polonica. 47 : 1 -- 78. 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 Nowak, Ronald M. 1999. Walker 's Mammals of the World, 6th edition. Johns Hopkins University Press, 1936 pp. ISBN 0 - 8018 - 5789 - 9 Simpson, George Gaylord ( 1945 ). `` The principles of classification and a classification of mammals ''. Bulletin of the American Museum of Natural History. 85 : 1 -- 350. Springer, Mark S. ; Stanhope, Michael J. ; Madsen, Ole ; Wilfried ( 2004 ). `` Molecules consolidate the placental mammal tree '' ( PDF ). Trends in Ecology and Evolution. 19 ( 8 ) : 430 -- 438. doi : 10.1016 / j. tree. 2004.05. 006. PMID 16701301. Vaughan, Terry A., James M. Ryan, and Nicholas J. Capzaplewski. 2000. Mammalogy : Fourth Edition. Saunders College Publishing, 565 pp. ISBN 0 - 03 - 025034 - X ( Brooks Cole, 1999 ) Wilson, Don E., and Deeann M. Reeder ( eds ). 1993. Mammal Species of the World. Smithsonian Institution Press, 1206 pp. ISBN 1 - 56098 - 217 - 9 Retrieved from `` https://en.wikipedia.org/w/index.php?title=Mammal_classification&oldid=836448377 '' Categories : Mammal taxonomy Systems of animal taxonomy Hidden categories : All articles with unsourced statements Articles with unsourced statements from January 2013 Articles needing additional references from January 2015 All articles needing additional references Talk Contents About Wikipedia Wikispecies Български Català Deutsch Español Français Galego Italiano Lëtzebuergesch Magyar Polski Română Русский Sicilianu Simple English Slovenčina Српски / srpski Türkçe 粵語 9 more Edit links This page was last edited on 14 April 2018, at 21 : 55 ( UTC ). Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. 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Question: where do mammals fit in the classification of animals
Answer: a class of animal within the Phylum Chordata