Anomodontia is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

group of non-mammalian

therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...

s from the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...

and

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest per ...

periods. By far the most speciose group are the

dicynodonts Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivorous animals with a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, typicall ...

, a clade of beaked, tusked

herbivores A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

.Chinsamy-Turan, A. (2011) ''Forerunners of Mammals: Radiation - Histology - Biology''
p.39.
Indiana University Press, . Retrieved May 2012 Anomodonts were very diverse during the

Middle Permian The Guadalupian is the second and middle series/ epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± ...

, including primitive forms like ''

Anomocephalus ''Anomocephalus'' is an extinct genus of primitive anomodonts and belongs to the clade Anomocephaloidea. The name is said to be derived from the Greek word ''anomos'' meaning lawless and ''cephalos'' meaning head. The proper word for head in Gre ...

'' and ''

Patranomodon ''Patranomodon'' (from Greek ''patr-'' “father”, thus “father of anomodonts”) is an extinct genus belonging to the group of Anomodontia. Rubidge and Hopson named this anomodont in 1990 after discovering its skull.Rubidge, B. S., & Hopson ...

'' and groups like

Venyukovioidea Venyukovioidea is an infraorder of anomodont therapsids related to dicynodonts from the Permian of Russia. They have also known as Venjukovioidea, as well as by the similar names Venyukoviamorpha or Venjukoviamorpha in literature. This in part ...

and

Dromasauria Dromasaurs are a paraphyletic group of anomodont therapsids from the Middle Permian. They were small with slender legs and long tails. Their skulls were short, but the eye sockets were large. Dromasauria was once considered to be a major group of ...

. Dicynodonts became the most successful and abundant of all herbivores in the

Late Permian Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

, filling ecological niches ranging from large browsers down to small burrowers. Few dicynodont families survived the

Permian–Triassic extinction event The Permian–Triassic (P–T, P–Tr) extinction event, also known as the Latest Permian extinction event, the End-Permian Extinction and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, ...

, but one lineage (

Kannemeyeriiformes Kannemeyeriiformes is a group of large-bodied Triassic dicynodonts. As a clade, Kannemeyeriiformes has been defined to include the species '' Kannemeyeria simocephalus'' and all dicynodonts more closely related to it than to the species ''Lystros ...

) evolved into large, stocky forms that became dominant terrestrial herbivores right until the

Late Triassic The Late Triassic is the third and final epoch of the Triassic Period in the geologic time scale, spanning the time between Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch ...

, when changing conditions caused them to decline, finally going extinct during the Triassic-Jurassic extinction event.

Classification

Taxonomy

* Order

Therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...

a * Suborder Anomodontia ** ''

Biseridens ''Biseridens'' ("two rows of teeth") is an extinct genus of anomodont therapsid, and one of the most basal anomodont genera known. Originally known from a partial skull misidentified as an eotitanosuchian in 1997, another well-preserved skull w ...

'' ** ''

'' **clade

Anomocephaloidea Anomocephaloidea is a clade (evolutionary grouping) of anomodont therapsids that existed in Gondwana during the Middle Permian and includes two species, ''Anomocephalus africanus'' from South Africa and ''Tiarajudens eccentricus'' from Brazil, bo ...

*** ''

'' *** ''

Tiarajudens ''Tiarajudens'' (" Tiaraju tooth") is an extinct genus of saber-toothed herbivorous anomodonts which lived during the Middle Permian period ( Capitanian stage) in what is now Rio Grande do Sul, Brazil. It is known from the holotype UFRGS P ...

'' ** Superfamily

*** Family

Otsheridae Otsheriidae is an extinct family of small herbivorous anomodont therapsids that are known from the Permian of Russia. See also * List of synapsids These lists of synapsids collectively include every genus that has ever been included in the cl ...

**** ''

Otsheria ''Otsheria'' is an extinct genus of anomodont from the Permian of Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with ...

'' **** ''

Suminia ''Suminia'' is an extinct genus of basal anomodont that lived during the Tatarian age of the late Permian, spanning approximately from 268-252 Ma.Rybczynski N. 2000. Cranial anatomy and phylogenetic position of Suminia getmanovi, a basal anomodon ...

'' *** Family

Venyukoviidae Venyukovioidea is an infraorder of anomodont therapsids related to dicynodonts from the Permian of Russia. They have also known as Venjukovioidea, as well as by the similar names Venyukoviamorpha or Venjukoviamorpha in literature. This in part ow ...

**** ''

Ulemica ''Ulemica'' is an extinct genus of venyukovioid therapsids, a type of anomodont related to dicynodonts. It lived during the Middle Permian period in what is now Russia, and is known from the Isheevo assemblage of the Amanakskaya Formation. The ...

'' **** ''

Venjukovia ''Venyukovia'' (named after its discoverer, Pavel N. Venyukov) is an extinct genus of venyukovioid therapsid, a basal anomodont from the Middle Permian of Russia. The type and sole species, ''V. prima'', is known only by a partial lower jaw with ...

'' **Clade

Chainosauria Chainosauria is a large and speciose clade of anomodont therapsid that includes the highly diverse dicynodonts and a small number of closely related basal genera (to the exclusion of Venyukovioidea and more basal anomodonts)—although the tota ...

*** ''

Galechirus ''Galechirus'' is an extinct genus of anomodont therapsids. It was about 30 cm (1 ft) long. Description ''Galechirus'' was lizard-like in appearance. It is considered to be a dicynodont by some paleontologists; others think ''Galech ...

'' *** ''

Galeops ''Galeops'' is an extinct genus of anomodont therapsids from the Middle-Late Permian of South Africa. It was described by Robert Broom in 1912. Some cladistic analyses have recovered it as closely related to dicynodonts. See also * List of ther ...

'' *** ''

Galepus ''Galepus'' is an extinct genus of anomodont therapsids. See also * List of therapsids This list of therapsids is an attempt to create a comprehensive listing of all genera that have ever been included in the Therapsida excluding mammals ...

'' ***Infraorder

Dicynodont Dicynodontia is an extinct clade of anomodonts, an extinct type of non-mammalian therapsid. Dicynodonts were herbivorous animals with a pair of tusks, hence their name, which means 'two dog tooth'. Members of the group possessed a horny, typic ...

Phylogeny

Cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

modified from Liu ''et al.'' (2009): Below is a cladogram from Kammerer ''et al.'' (2013). The data matrix of Kammerer ''et al.'' (2013), a list of characteristics that was used in the analysis, was based on that of Kammerer ''et al.'' (2011), which followed a comprehensive taxonomic revision of ''

Dicynodon ''Dicynodon'' ("two dog-teeth") is a genus of dicynodont therapsid that flourished during the Upper Permian period. Like all dicynodonts, it was herbivorous animal. This reptile was toothless, except for prominent tusks, hence the name. It probab ...

''. Because of this, many of the relationships found by Kammerer ''et al.'' (2013) are the same as those found by Kammerer ''et al.'' (2011). However, several taxa were added to the analysis, including ''

'' ''

Eubrachiosaurus ''Eubrachiosaurus'' is an extinct genus of stahleckeriid dicynodont known from the Late Triassic (Carnian stage) of Wyoming, United States. Description ''Eubrachiosaurus'' is known only from the holotype specimen FMNH UC 633, a partial ...

'', '' Shaanbeikannemeyeria'', ''

Zambiasaurus ''Zambiasaurus'' is an extinct genus of dicynodonts that was discovered in the Middle Triassic (Anisian) Ntawere Formation of Zambia, southern Africa. It was a large dicynodont, reconstructed using several fossil fragments, in majority belonging ...

'' and many "outgroup" taxa (positioned outside Anomodontia), while other taxa were re-coded. As in Kammerer ''et al.'' (2011), the interrelationships of non-

kannemeyeriiform Kannemeyeriiformes is a group of large-bodied Triassic dicynodonts. As a clade, Kannemeyeriiformes has been defined to include the species ''Kannemeyeria simocephalus'' and all dicynodonts more closely related to it than to the species '' Lystro ...

dicynodontoids are weakly supported and thus vary between the analyses.

References

{{Taxonbar, from=Q131803 Fossil taxa described in 1859 Guadalupian first appearances Late Triassic extinctions Taxa named by Richard Owen