Pylaecephalidae

"Robertiidae" redirects here. For the nematode family Robertiidae Travassos & Kloss, 1961, see Traklosiidae.

Pylaecephalidae is a family of dicynodont therapsids that includes Diictodon, Robertia, and Prosictodon from the Permian of South Africa. Pylaecephalids were small burrowing dicynodonts with long tusks. The family was first named in 1934 and was redefined in 2009.^[1] Diictodontidae and Robertiidae are considered junior synonyms of Pylaecephalidae;^[2] although Pylaecephalus itself is considered a junior synonym of Diictodon,^[3] the name Pylaecephalidae predates these names and therefore takes priority.^[1]

Pylaecephalidae Temporal range: Permian
Fossil of Diictodon
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Clade:	Therapsida
Clade:	†Anomodontia
Clade:	†Dicynodontia
Family:	†Pylaecephalidae van Hoepen, 1934
Type genus
†Pylaecephalus Van Hoepen, 1934
Genera
†Diictodon †Eosimops †Prosictodon †Robertia
Synonyms
Diictodontidae Cluver and King, 1983 Robertiidae Cluver and King, 1983

Phylogeny

Below is a cladogram modified from Angielczyk et al. (2021):^[4]

Pylaecephalidae	Diictodon Prosictodon Eosimops Robertia