Probainognathia

The probainognathians are members of one of the two major clades of the infraorder Eucynodontia, the other being Cynognathia. The earliest forms were carnivorous and insectivorous, though some groups eventually also evolved herbivorous diets. The earliest and most basal probainognathian is Lumkuia, from South Africa. Three groups survived the extinction at the end of Triassic: Tritheledontidae and Tritylodontidae, which both survived until the Jurassic—the latter even into the Cretaceous (Montirictus and Xenocretosuchus)—and Mammaliaformes, which gave rise to the mammals.[2]

Probainognathia Temporal range: Middle Triassic–Holocene PreꞒ Ꞓ O S D C P T J K Pg N
Fossil of the probainognathian Chiniquodon theotonicus in the Staatliches Museum für Naturkunde Stuttgart
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Therapsida
Clade:	Cynodontia
Clade:	Eucynodontia
Clade:	Probainognathia Hopson, 1990
Subgroups
†Lumkuia †Ecteniniidae †Chiniquodontidae †Probainognathidae †Candelariodon[1] †Protheriodon[1] Prozostrodontia

Phylogeny

Partial skeleton of an unidentified probainognathian from Madagascar in the Field Museum of Natural History, Chicago

Below is a cladogram from Ruta, Botha-Brink, Mitchell and Benton (2013) showing one hypothesis of cynodont relationships:[3]

Eucynodontia

†Cynognathia   Probainognathia   †Lumkuia       †Ecteninion         †Aleodon     †Chiniquodon         †Probainognathus       †Trucidocynodon       †Therioherpeton     †Tritheledontidae   †Riograndia         †Chaliminia     †Elliotherium         †Diarthrognathus     †Pachygenelus           †Brasilodontidae   †Brasilitherium     †Brasilodon       †Tritylodontidae   †Oligokyphus       †Kayentatherium       †Tritylodon     †Bienotherium         Mammaliaformes   †Sinoconodon       †Morganucodon     Mammalia

See also

• Evolution of mammals
• List of prehistoric mammals

References

1. Martinelli, A.; Soares, M. B.; Oliveira, T.; Rodrigues, P.; Schultz, C. (2017). "The Triassic eucynodont Candelariodon barberenai revisited and the early diversity of stem prozostrodontians". Acta Palaeontologica Polonica. 62. doi:10.4202/app.00344.2017.
2. The slow and fast steps to becoming a mammal
3. Ruta, M.; Botha-Brink, J.; Mitchell, S. A.; Benton, M. J. (2013). "The radiation of cynodonts and the ground plan of mammalian morphological diversity". Proceedings of the Royal Society B: Biological Sciences. 280 (1769): 20131865. doi:10.1098/rspb.2013.1865. PMC 3768321. PMID 23986112.