Holotheria is a diverse group of

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s that are descendants of the last common ancestor of ''

Kuehneotherium ''Kuehneotherium'' is an early mammaliaform genus, previously considered a Holotheria, holothere, that lived during the Late Triassic-Early Jurassic Epochs and is characterized by reversed-triangle pattern of Molar (tooth), molar Cusp (anatomy), ...

'' (now known to be a non-mammalian cynodont) and

Theria Theria ( or ; ) is a scientific classification, subclass of mammals amongst the Theriiformes. Theria includes the eutherians (including the Placentalia, placental mammals) and the metatherians (including the marsupials) but excludes the egg-lay ...

(the group that includes

marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...

s and

placental mammal Placental mammals ( infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguish ...

s).Wible, J. R., Rougier, G. W., Novacek, M. J. & McKenna, M. C. (2001). "Earliest eutherian ear region: A petrosal referred to ''Prokennalestes'' from the Early Cretaceous of Mongolia." ''American Museum Novitates'', 3322. The group is characterized by the beginning of the triangulation of a typical triconodont dentition in morganucodonts, towards a symmetrodonta. This triangulation occurs convergently in Docodontiformes although

Shuotheriidae Shuotheriidae is a small family of Jurassic mammaliaforms whose remains are found in China, Great Britain and possibly Russia. They have been proposed to be close relatives of Australosphenida (which often controversially includes monotremes), t ...

was formerly considered sister to

Australosphenida The Australosphenida are a clade of mammals, containing mammals with tribosphenic molars, known from the Jurassic to Mid-Cretaceous of Gondwana. Although they have often been suggested to have acquired tribosphenic molars independently from those ...

. There are studies that place

Docodonta Docodonta is an Order (biology), order of extinct Mesozoic Mammaliaformes, mammaliaforms (advanced cynodonts closely related to true Crown group, crown-group mammals). They were among the most common mammaliaforms of their time, persisting from t ...

as sister to Monotremata, which would make Docodontiformes fall within Pan-Monotremata instead of being a clade outside Holotheria. Holotheria fell into disuse and was widely considered invalid by the early 2000s, but Mao et al. in 2024 revived the clade due to them finding

Allotheria Allotheria (meaning "other beasts", from the Ancient Greek language, Greek , '–other and , '–wild animal) is an extinct clade of mammals known from the Mesozoic and early Cenozoic. Shared characteristics of the group are the presence of lower ...

(the group containing multituberculates and their relatives) outside crown group of mammals.

Classification

According to McKenna/Bell (1997): * Class

Mammalia A mammal () is a vertebrate animal of the class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle ear bon ...

** Subclass

Theriiformes Theriiformes is a clade of mammals. The term was coined by Timothy B. Rowe in his doctoral dissertation, and is defined as the clade formed by the most recent common ancestor of multituberculates (which form part of the broader group Allotheria ...

*** Infraclass Holotheria **** Genus '' Chronoperates''? **** Superlegion Kuehneotheria ***** Genus ''

Woutersia ''Woutersia'' was a Triassic genus of ' symmetrodont' and the only representative of the family Woutersiidae. It was originally classified as a kuehneotheriid, but it has been suggested that it may be related to Docodonta. Remains of ''W. mirabi ...

'' ***** Family

Kuehneotheriidae Kuehneotheriidae is an extinct family of mammaliaforms traditionally placed within 'Symmetrodonta', though now generally considered more basal than true symmetrodonts. All members of Kuehneotheriidae which have been found so far are represented o ...

**** Superlegion Trechnotheria ***** Legion

Symmetrodonta Symmetrodonta is a group of Mesozoic mammals and mammal-like synapsids characterized by the triangular aspect of the molars when viewed from above, and the absence of a well-developed talonid. The traditional group of 'symmetrodonts' ranges in ...

* ****** Genus '' Casamiquelia''? ****** Genus '' Thereuodon''? ****** Genus '' Atlasodon''? ****** Genus '' Eurylambda''? ****** Genus '' Peralestes''? ****** Genus ''

Shuotherium ''Shuotherium'' is a fossil mammaliaform known from Middle Jurassic, Middle-Late Jurassic of the Forest Marble Formation of England,Sigogneau−Russell, D. 1998. Discovery of a Late Jurassic Chinese mammal in the upper Bathonian of England. Compt ...

''? ****** Order Amphidontoidea ******* Family Amphidontidae ****** Order Spalacotherioidea ******* Genus '' Gobiotheriodon''? ******* Genus ''

Maotherium ''Maotherium'' is a genus extinct symmetrodont mammal that was discovered in Early Cretaceous rocks in Liaoning Province, China, in 2003. Its scientific name directly translates to "fur beast", in reference to the impressions of fur around the f ...

'' ******* Genus '' Zhangheotherium'' ******* Family

Tinodontidae Tinodontidae is an extinct family of actively mobile mammals, endemic to what would now be North America, Asia, Europe, and Africa during the Jurassic and Cretaceous periods. Taxonomy ''Tinodontidae'' was named by Marsh (1887). It was assigned ...

******* Family Barbereniidae? ******** Genus '' Guirogatherium''? ******** Genus '' Barberenia''? ******* Family

Spalacotheriidae Spalacotheriidae is a family of extinct mammals belonging to the paraphyletic group ' Symmetrodonta'. They lasted from the Early Cretaceous to the Campanian in North America, Europe, Asia and North Africa. Spalacotheriids are characterised by ha ...

******** Genus '' Microderson'' ******** Genus '' Shalbaatar'' ******** Genus ''

Spalacotherium ''Spalacotherium'' is a genus of extinct mammal from the Early Cretaceous of Europe. The type species ''Spalacotherium tricuspidens'' was originally named by Richard Owen in 1854, and its material includes maxillary and dentary fragments and many ...

'' ******** Subfamily Spalacolestinae ********* Genus ''

Symmetrolestes ''Symmetrolestes'' is an extinct genus of small spalacotheriid mammal from the Early Cretaceous period of Japan. The genus contains one species known as ''S. parvus'', the type fossil (which is only fossil known) is from fluvial deposits located ...

'' ********* Genus ''

Akidolestes ''Akidolestes'' is an extinct genus of mammals of the family Spalacotheriidae, a group of mammals related to therians (the subclass containing marsupials and placentals). The genus name, ''Akidolestes'', is derived from ''akido'', Greek for p ...

'' ********* Genus '' Heishanlestes'' ********* Genus '' Spalacotheroides'' ********* Genus '' Spalacotheridium'' ********* Genus '' Spalacolestes'' ********* Genus '' Symmetrodontoides'' ***** Legion

Cladotheria Cladotheria is a clade (sometimes ranked as a legion) of mammals. It contains modern therian mammals (marsupials and placentals) and several extinct groups, such as the "dryolestoids", amphitheriids and peramurids. The clade was named in 1975 ...

****** Genus '' Butlerigale''? ****** Family

Ausktribosphenidae Ausktribosphenidae is an extinct family of australosphenidan mammals from the Early Cretaceous of Australia and mid Cretaceous of South America. Classification and taxonomy Ausktribosphenidae is closely related to monotremes and hence the two ...

? ****** Sublegion

Dryolestoidea Dryolestida is an extinct order of mammals, known from the Jurassic and Cretaceous. They are considered Basal (phylogenetics), basal members of the clade Cladotheria, close to the ancestry of therian mammals. It is also believed that they develop ...

******* Order Dryolestida ******* Order Amphitheriida ****** Sublegion

Zatheria Cladotheria is a clade (sometimes ranked as a Legion (taxonomy), legion) of mammals. It contains modern therian mammals (marsupials and Placentalia, placentals) and several extinct groups, such as the "dryolestoids", amphitheriids and peramurids. ...

******* Infralegion Peramura ******* Infralegion

Tribosphenida Tribosphenida is a clade of mammals that includes the ancestor of ''Hypomylos'', Aegialodontia and Theria (the last common ancestor of marsupials and placentals plus all of its descendants). It belongs to the group Zatheria. The current definitio ...

******** Genus '' Ambondro''? ******** Genus '' Hypomylos''? ******** Genus '' Montanalestes''? ******** Genus '' Tribactonodon''? ******** Supercohort

Aegialodontia Aegialodontia is a clade of extinct early mammals, close to the origin of Boreosphenida. The clade includes some of the oldest known tribosphenic taxa, until the discovery of '' Tribactonodon'' from the Berriasian Durlston Formation in 2001, '' A ...

********* Family Aegialodontidae ********** Genus '' Aegialodon'' ********** Genus '' Kielantherium'' ******** Supercohort

********* Order

Deltatheroida Deltatheroida is an extinct group of basal metatherians that were distantly related to modern marsupials. The majority of known members of the group lived in the Cretaceous; one species, '' Gurbanodelta kara'', is known from the late Paleocene ( ...

********* Order

Asiadelphia ''Asiatherium'' is an extinct genus of mammal, probably belonging to Metatheria. It lived during the Late Cretaceous, and its fossilized remains were discovered in Mongolia. Description Skull of ''Asiatherium'' is in length. This animal was ro ...

********* Cohort

Marsupialia Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a ...

********** Magnorder

Australidelphia Australidelphia is a superorder of marsupials encompassing about three-quarters of all living marsupial species, including all those native to Australasia and one South American species, the monito del monte. Unlike other American marsupials, wh ...

********** Superorder

Microbiotheria Microbiotheria is an australidelphian marsupial order that encompasses two families, Microbiotheriidae and Woodburnodontidae, and is represented by only one extant species, the monito del monte, and a number of extinct species known from foss ...

********** Superorder Eometatheria ************ Order Yalkaparidontia ************ Order

Notoryctemorphia Notoryctidae are a family of marsupials comprising the marsupial moles and their fossil relatives. It is the only family in the order Notoryctemorphia. Taxonomy A fossil species in a new genus was published as '' Naraboryctes''. A new diagnos ...

*********** Grandorder

Dasyuromorphia Dasyuromorphia (, meaning "hairy tail" in Greek) is an order comprising most of the Australian carnivorous marsupials, including quolls, dunnarts, the numbat, the Tasmanian devil, and the extinct thylacine. In Australia, the exceptions include ...

*********** Grandorder Syndactyli ************ Order Peramelia ************ Order

Diprotodontia Diprotodontia (, from Greek language, Greek "two forward teeth") is the largest extant order (biology), order of marsupials, with about 155 species, including the kangaroos, Wallaby, wallabies, Phalangeriformes, possums, koala, wombats, and many ...

********** Magnorder

Ameridelphia Ameridelphia is traditionally a superorder that includes all marsupials living in the Americas except for the monito del monte (''Dromiciops''). It is now regarded as a paraphyletic group. Orders The orders within this group are listed below: ...

********* Cohort

Placentalia Placental mammals ( infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distingui ...

************ Order

Bibymalagasia ''Plesiorycteropus'', also known as the bibymalagasy or Malagasy aardvark, is a recently extinct genus of mammals from Madagascar. Upon its description in 1895, it was classified with the aardvark, but more recent molecular evidence instead sug ...

********** Magnorder

Xenarthra Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a superorder and major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and ...

********** Magnorder

Epitheria Epitherians comprise all the placental mammals except the Xenarthra. They are primarily characterized by having a stirrup-shaped stapes in the middle ear, which allows for passage of a blood vessel. This is in contrast to the column-shaped stapes ...

According to Wang, Clemens, Hu & Li, 1998 * Class

** Subclass

*** Infraclass Holotheria **** Genus '' Chronoperates''? **** Superlegion Kuehneotheria **** Superlegion Trechnotheria ***** Family Amphidontidae ***** Superfamily Spalacotheroidea ***** Legion

****** Genus ''

Asfaltomylos ''Asfaltomylos'' is an extinct genus of the primitive mammal subclass Australosphenida from the Jurassic of Argentina. The type and only species is ''Asfaltomylos patagonicus'', recovered from and named after the Cañadón Asfalto Formation, Ca ...

''? ****** Genus '' Atlasodon''? ****** Family

? ****** Genus '' Casamiquelia''? ****** Genus '' Thereuodon''? ****** Genus '' Eurylambda''? ****** Genus ''

'' ***** Legion

****** Genus '' Butlerigale''? ****** Sublegion

******* Order Dryolestida ******* Order Amphitheriida ******* Genus '' Amphitherium'' ****** Sublegion

******* Genus '' Arguitherium''? ******* Genus '' Arguimus''? ******* Genus '' Nanolestes''? ******* Genus '' Vincelestes''? ******* Infralegion Peramura ******* Infralegion

References

Mammal unranked clades Taxa named by John R. Wible Theriiformes {{paleo-mammal-stub