Eutheria
| Eutherians
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 Fossil specimen of Eomaia scansoria, an early eutherian
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| Scientific classification | ||||||||
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In some taxonomic classification schemes, Eutheria is the term used for one of the three major branches or clades of mammals that includes extant members, the other two groups being the marsupials and the monotremes. Eutheria is often presented as an infraclass within the subclass Theria within the class Mammalia, with the other Infraclass within Theria being Metatheria (marsupials and their nearest ancestors). As used in this sense, Eutheria includes all extant placentals and those extinct mammals that share a more recent common ancestor with placentals than they do with Metatheria. The order Montremata (echidnas and platypuses) are often placed within the subclass Prototheria.
Extant eutherians, their last common ancestor, and all extinct descendants of that ancestor are placentals. Except for the Virginia opossum, which is a metatherian, all mammals indigenous to Europe, Africa, Asia, and North America north of Mexico are eutherians. There are over 1000 extant genera and over 4000 extant species of eutherians, ranging from shrews to whales and from aquatic cetaceans to the volant bats to the terrestrial primates.
However, not all classification schemes utilize the term Eutheria. For example, the popular scheme of McKenna and Bell recognize the two cohorts of Placentalia and Marsupialia, choosing not to use Eutheria. In this sense, Placentalia is used synonymous with Eutheria.
Eutherians are distinguished from noneutherians by various features of the feet, ankles, jaws, and teeth. One of the major differences between placental and nonplacental eutherians is that placentals lack epipubic bones, which are present in all other fossil and living mammals (marsupials and monotremes).
Overview
Mammals (class Mammalia) are a clade of endothermic amniotes distinguished from the reptiles and the birds by the possession of hair, three middle ear bones, mammary glands in females, and a neocortex (a region of the brain). The mammalian brain regulates body temperature and the circulatory system, including the four-chambered heart. The basic body type is a four-legged land-borne animal, but some mammals are adapted for life at sea, in the air, in the trees, or on two legs.
In some classifications, the mammals are divided into two subclasses (not counting fossils): the Prototheria (order of Monotremata) and the Theria, the latter composed of the infraclasses Metatheria and Eutheria. The marsupials constitute the crown group of the Metatheria and therefore include all living metatherians as well as many extinct ones; the placentals likewise constitute the crown group of the Eutheria.
While the classification of mammals at the family level has been relatively stable, different treatments at higher levels—subclass, infraclass, and order—appear in contemporaneous literature, especially for the marsupials. Much recent change has reflected the results of cladistic analysis and molecular genetics. Results from molecular genetics, for example, have led to the adoption of new groups such as the Afrotheria and the abandonment of traditional groups such as the Insectivora.
Eutheria comes from the Greek ευ-, eu-, meaning "true/good" and θηρίον, thērion, meaning "beast," and thus "true beasts." Gill named the group in 1872 but applied the term to both placentals and marsupials; Huxley in 1880 recognized the term as used today where placentals are included and marsupials excluded and where the term is meant to encompass a more broadly defined group than Placentalia (Archibald 2001).
Characteristics
Mammals are all endotherms and amniote vertebrates. As with other mammals, eutherians are endotherms and amniote vertebrates, and have at most two generations of teeth, unlike reptiles in which there can be many generations of teeth. In mammals, the articular and quadrate, which composes the jaw joint in reptiles, is incorporated into the middle ear as the outermost two ear ossicles (malleus and incus; reptiles have only one ear ossicle, thte columnella). While in birds and reptiles, the large aorta leaving the heart bends to the right, in mammals it bends to the left (Archibald 2001).
The features of Eutheria that distinguish them from metatherians, a group that includes modern marsupials, are:
- an enlarged malleolus ("little hammer") at the bottom of the tibia, the larger of the two shin bones (Ji et al. 2002).
- the joint between the first metatarsal bone and the entocuneiform bone in the foot is offset further back than the joint between the second metatarsal and middle cuneiform bones—in metatherians these joints are level with each other (Ji et al. 2002).
- various features of jaws and teeth (Ji et al. 2002).
Evolutionary history
The oldest known eutherian species is Juramaia sinensis, dated at from the Jurassic in China.[2]
Eutheria contains several extinct genera and larger groups, many with complicated taxonomic history that is still unresolved. Members of the Adapisoriculidae, Cimolesta and Leptictida have been previously placed within the out-dated placental group "Insectivora", while Zhelestids have been considered primitive ungulates.[3] However, more recent studies have suggested these enigmatic taxa represent stem group eutherians, more basal to Placentalia.[4][5]
| The fossil eutherian species believed to be the oldest known is Juramaia sinensis, which lived about .[2] Montanalestes was found in North America, while all other nonplacental eutherian fossils have been found in Asia. The earliest known placental fossils have also been found in Asia.[6] | |
† = extinct |
Taxonomy
The rank of "Theria" may vary depending on the classification system used. The textbook classification system by Vaughan et al. (2000)[7] gives the following:
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Class Mammalia
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In the above system Theria is a subclass. Alternatively, in the system proposed by McKenna and Bell (1997)[8] it is ranked as a supercohort under the subclass Theriiformes:
|
Class Mammalia
|
Another classification proposed by Luo et al. (2002)[9] does not assign any rank to the taxonomic levels, but uses a purely cladistic system instead.
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 here 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 listed here, families are merely listed under the order to which they belong. Please see the pages associated with specific orders to see more detailed relationships among families in that 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, potaroos 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)
- Order Didelphimorphia
- Infraclass Eutheria
- Order Xenarthra
- Family Bradypodidae
- Family Megalonychidae
- Family Dasypodidae
- Family Myrmecophagidae
- Order Insectivora
- 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
- Order Xenarthra
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 the most comprehensive work to date on the systematics, relationships, and occurrences of all mammal taxa, living and extinct, down through the rank of genus. The new McKenna/Bell classification was quickly accepted by paleontologists. 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.
The published re-classification forms both a comprehensive and authoritative record of approved names and classifications and a list of invalid names.
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
- Order †Multituberculata: multituberculates
- Infraclass †Triconodonta
- Family †Austrotriconodontidae
- 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 †Dryolestidae
- Family †Paurodontidae
- Family †Donodontidae
- Family †Mesungulatidae
- Family †Reigitheriidae
- Family †Brandoniidae
- Order †Amphitheriida
- Family †Amphitheriidae
- Order †Dryolestida
- 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
- Cohort Marsupialia: marsupials
- Family †Yingabalanaridae
- Family †Stagodontidae
- Family †Pediomyidae
- 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
- Order Peramelia: bandicoots
- Order †Yalkaparidontia
- Superorder Microbiotheria
- 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 †Patagoniidae
- Family †Groeberiidae
- Family †Glasbiidae
- Family †Caroloameghiniidae
- Order †Sparassodonta
- Family †Mayulestidae
- Family †Hondadelphidae
- Family †Borhyaenidae
- Order Didelphimorphia: opossums
- Cohort Placentalia: placentals
- Order †Bibymalagasia
- Magnorder Xenarthra: edentates
- Order Cingulata: armadillos and relatives
- Family Dasypodidae: armadillos
- Family †Peltephilidae
- Family †Pampatheriidae
- Family †Palaeopeltidae
- Family †Glyptodontidae: glyptodonts
- Order Pilosa: anteaters, sloths, and relatives
- Family †Entelopidae
- Family Myrmecophagidae: giant anteaters and relatives
- Family Cyclopedidae: pygmy anteater
- Family †Rathymotheriidae
- Family †Scelidotheriidae
- Family †Mylodontidae
- Family †Megatheriidae: ground sloths
- Family Megalonychidae: two-toed sloths
- Family Bradypodidae: three-toed sloths
- Order Cingulata: armadillos and relatives
- 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
- Order †Mimotonida
- Mirorder Simplicidentata
- Order †Mixodontia
- Family †Eurymylidae
- Order Rodentia: rodents
- Family †Alagomyidae
- Family †Laredomyidae
- Family †Ischyromyidae
- Family †Allomyidae
- Family Aplodontiidae: mountain beaver
- Family †Mylagaulidae
- Family †Theridomyidae
- Family †Reithroparamyidae
- Family Sciuridae: squirrels
- Family †Eutypomyidae
- Family Castoridae: beavers
- Family †Rhizospalacidae
- Family †Protoptychidae
- Family †Armintomyidae
- Family Dipodidae: jumping mice, jerboas
- Family †Simimyidae
- Family Muridae: rats, mice, and relatives
- Family Myoxidae: dormice
- Family †Eomyidae
- Family †Florentiamyidae
- Family Geomyidae: pocket gophers, pocket mice, and kangaroo rats
- Family Pedetidae: springhaas
- Family †Parapedetidae
- Family †Zegdoumyidae
- Family Anomaluridae: scaly-tailed squirrels
- Family †Ivanantoniidae
- Family †Sciuravidae
- Family †Chapattimyidae
- Family †Cylindrodontidae
- Family Ctenodactylidae: gundis
- Family †Tsaganomyidae
- 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
- Family Bathyergidae: mole-rats
- Family †Bathyergoididae
- 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
- Order †Mixodontia
- Grandorder Ferae
- Order Cimolesta - pangolins and relatives
- Family †Palaeoryctidae
- Family †Cimolestidae
- Family †Apatemyidae
- Family †Stylinodontidae
- Family †Tillotheriidae
- Family †Wangliidae
- Family †Harpyodidae
- Family †Bemalambdidae
- Family †Pastoralodontidae
- Family †Titanoideidae
- Family †Pantolambdidae
- Family †Barylambdidae
- Family †Cyriacotheriidae
- Family †Pantolambdodontidae
- Family †Coryphodontidae
- Family †Pantolestidae
- Family †Paroxyclaenidae
- Family †Ptolemaiidae
- Family †Epoicotheriidae
- Family †Metacheiromyidae
- Family Manidae: pangolins
- Family †Ernanodontidae
- Order †Creodonta: creodonts
- Family †Hyaenodontidae
- Family †Oxyaenidae
- Order Carnivora
- 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
- Family †Miacidae
- Family Canidae: dogs
- Family †Amphicyonidae
- Family Ursidae: bears
- Family †Hemicyonidae
- Family Otariidae: eared seals
- Family Phocidae: seals, walrus
- Family Mustelidae: weasels, skunks, and relatives
- Family Procyonidae: ringtails, olingos, kinkajou, raccoons, coatis, red panda
- Order Cimolesta - pangolins and relatives
- 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
- Order Chrysochloridea
- Family †Adapisoriculidae
- 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
- Order Chiroptera: bats
- 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
- Order †Procreodi
- 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
- Order Perissodactyla: odd-toed ungulates
- Order Tubulidentata
- Grandorder Anagalida
- Superorder †Leptictida
- Sublegion †Dryolestoidea
- Legion †Symmetrodonta
Theria ({{#invoke:IPAc-en|main}}{{#invoke:IPAc-en|main}}{{#invoke:IPAc-en|main}}/iə/; Greek: θηρίον, wild beast) is a subclass of mammals[10] that give birth to live young without using a shelled egg, consisting of the eutherians (including the placental mammals) and the metatherians (including the marsupials). The only omitted extant mammal group is the egg-laying monotremes.
The earliest known therian mammal fossil is Juramaia, from the Middle Jurassic of China. However, molecular data suggests that therians may have originated even earlier, during the Early Jurassic.[11]
ReferencesISBN links support NWE through referral fees
- ↑ D. L. Rock, and J. P. Hunter, "Rooting Around the Eutherian Family Tree: The Origin and Relations of the Taeniodonta," Journal of Mammalian Evolution 21(issue 1)(2014): 75-91.
- ↑ 2.0 2.1 Luo, Z. and C. Yuan, Q. Meng, and Q. Ji (2011). A Jurassic eutherian mammal and divergence of marsupials and placentals. Nature 476 (7361): 42–45.
- ↑ Rose, Kenneth D. (2006). The beginning of the age of mammals. Baltimore: Johns Hopkins University Press. ISBN 9780801892219.
- ↑ Wible, J. R. and Rougier, G. W.; Novacek, M. J.; Asher, R. J. (2007). Cretaceous eutherians and Laurasian origin for placental mammals near the K/T boundary. Nature 447 (7147): 1003–1006.
- ↑ Wible, John R. and Rougier, Guillermo W.; Novacek, Michael J.; Asher, Robert J. (2009). The Eutherian Mammal Maelestes gobiensis from the Late Cretaceous of Mongolia and the phylogeny of cretaceous eutheria. Bulletin of the American Museum of Natural History 327: 1–123.
- ↑ 6.0 6.1 Cite error: Invalid
<ref>tag; no text was provided for refs namedJiLuoYuan2002EarliestEutherian - ↑ Vaughan, Terry A., James M. Ryan, and Nicholas J. Czaplewski. 2000. Mammalogy: Fourth Edition. Saunders College Publishing, 565 pp. ISBN 0-03-025034-X
- ↑ 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
- ↑ Luo, Z.-X., Z. Kielan-Jaworowska, and R. L. Cifelli. 2002. In quest for a phylogeny of Mesozoic mammals. Acta Palaeontologica Polonica, 47:1-78.
- ↑ Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. Subclass Theria. Animal Diversity Web.
- ↑ Hugall, A.F. et al. (2007) Calibration choice, rate smoothing, and the pattern of tetrapod diversification according to the long nuclear gene RAG-1. Syst Biol. 56(4):543-63.
| Mammals |
|---|
| Monotremata (platypus, echidnas) |
|
Marsupialia: | Paucituberculata (shrew opossums) | Didelphimorphia (opossums) | Microbiotheria | Notoryctemorphia (marsupial moles) | Dasyuromorphia (quolls and dunnarts) | Peramelemorphia (bilbies, bandicoots) | Diprotodontia (kangaroos and relatives) |
|
Placentalia: Cingulata (armadillos) | Pilosa (anteaters, sloths) | Afrosoricida (tenrecs, golden moles) | Macroscelidea (elephant shrews) | Tubulidentata (aardvark) | Hyracoidea (hyraxes) | Proboscidea (elephants) | Sirenia (dugongs, manatees) | Soricomorpha (shrews, moles) | Erinaceomorpha (hedgehogs and relatives) Chiroptera (bats) | Pholidota (pangolins)| Carnivora | Perissodactyla (odd-toed ungulates) | Artiodactyla (even-toed ungulates) | Cetacea (whales, dolphins) | Rodentia (rodents) | Lagomorpha (rabbits and relatives) | Scandentia (treeshrews) | Dermoptera (colugos) | Primates | |
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