Pylaecephalidae is a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

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, typicall ...

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 ...

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Diictodon ''Diictodon'' is an extinct genus of pylaecephalid dicynodont. These mammal-like synapsids lived during the Late Permian period, approximately 255 million years ago. Fossils have been found in the ''Cistecephalus'' Assemblage Zone of the Mad ...

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Robertia ''Robertia'' is an extinct genus of small herbivorous dicynodonts from the Middle to Late Permian of South Africa, between 260 and 265 million years ago. It is a monospecific genus, consisting of the type-species ''R. broomiana,'' which was clas ...

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Prosictodon ''Prosictodon'' is an extinct genus of pylaecephalid dicynodont from Middle Permian of South Africa. It was first named by Kenneth D. Angielczyk and Bruce S. Rubidge in 2010 File:2010 Events Collage New.png, From top left, clockwise: The 2010 ...

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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 Paleoz ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

. Pylaecephalids were small burrowing dicynodonts with long tusks. The family was first named in 1934 and was redefined in 2009. Diictodontidae and Robertiidae are considered

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

s of Pylaecephalidae; although ''Pylaecephalus'' itself is considered a junior synonym of ''Diictodon'',Sullivan, C., & Reisz, R. R. (2005)
CRANIAL ANATOMY AND TAXONOMY OF THE LATE PERMIAN DICYNODONT DIICTODON.
Annals of Carnegie Museum, 74(1), 45–75. the name Pylaecephalidae predates these names and therefore takes priority.

References

Prehistoric synapsids of Africa Dicynodonts Permian synapsids Permian first appearances Permian extinctions Prehistoric therapsid families {{anomodont-stub