Eucynodontia

Eucynodontia ("true dog teeth") is a clade of cynodont therapsids including mammals and most non-mammalian cynodonts. The oldest eucynodonts are known from the Early Triassic and possibly Late Permian. Eucynodontia includes two major subgroups, Cynognathia and Probainognathia.^[1]

Eucynodonts Temporal range: Early Triassic-Holocene, 251–0 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Examples of eucynodonts. 1st row: Trirachodon berryi, Probainognathus jenseni; 2nd row: Brasilitherium riograndensis, Castorocauda lutrasimilis; 3rd row: Ornithorhynchus anatinus (platypus), Loxodonta africana (African bush elephant).
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Clade:	Therapsida
Clade:	Cynodontia
Clade:	Epicynodontia
Clade:	Eucynodontia Kemp, 1982
Subgroups
†Kataigidodon †Cynognathia Probainognathia

The clade was named in 1982 by Thomas Kemp, who defined it as all cynodonts more derived than Thrinaxodon.^[2][3]

In 2001, Hopson and Kitching redefined the clade Eucynodontia as the least inclusive group containing Mammalia and Exaeretodon.^[4]

Phylogeny

Cladogram after Stefanello et al. (2023):^[5]

	Procynosuchus
	Galesaurus Thrinaxodon Platycraniellus Eucynodontia Cynognathia Cynognathus Gomphodontia Diademodon Langbergia Trirachodon Sinognathus Traversodontidae Pascualgnathus Luangwa Scalenodon Mandagomphodon Massetognathus Exaeretodon Probainognathia Lumkuia Chiniquodon Probainognathidae Probainognathus Bonacynodon Ecteniniidae Trucidocynodon Ectenion (sic) Diegocanis Protheriodon Prozostrodontia Prozostrodontidae Prozostrodon Pseudotherium Therioherpeton Irajatherium Riograndia Diarthrognathus Pachygenelus Tritylodontidae Botucaraitherium Brasilodon Mammaliaformes