Probainognathia

Probainognathia Temporal range: Middle Triassic - Late Jurassic (non-mammalian)
Fossil of the probainognathian Chiniquodon theotonicus in the Staatliches Museum für Naturkunde Stuttgart
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Order:	Therapsida
Suborder:	Cynodontia
Infraorder:	Eucynodontia
Parvorder:	Probainognathia
Subgroups
Ecteniniidae Lumkuiidae Chiniquodontoidea

The Probainognathians are members of one of the two major clades of the infraorder Eucynodontia, the other being Cynognathians. The earliest forms were carnivorous and insectivorous, though some species eventually also evolved herbivorous traits. The earliest and most basal Probainognathian is Lumkuia, from South Africa. Three groups survived the extinction at the end of Triassic; the Tritheledontidae and Tritylodontidae, who both survived until the Jurassic - the latter possibly even into the Cretaceous (Xenocretosuchus), and Mammaliaformes, who gave rise to the mammals.^[1]

Classification

Taxonomy

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

• Suborder Cynodontia
  • Infraorder Eucynodontia
    • (unranked) Probainognathia
      • ? Family Ecteniniidae
      • Family Lumkuiidae
      • Superfamily Chiniquodontoidea
        • Family Chiniquodontidae
        • ? Family Ecteniniidae
        • Family Probainognathidae
        • (unranked) Prozostrodontia
          • Prozostrodon
          • Family Brasilodontidae
          • Family Dromatheriidae
          • Family Therioherpetidae
          • Family Tritheledontidae / (unranked) Ictidosauria
          • Family Tritylodontidae
          • (unranked) Mammaliaformes
            • Class Mammalia

Phylogeny

Below is a cladogram from Ruta, Botha-Brink, Mitchell and Benton (2013) showing one hypothesis of cynodont relationships:^[2]

Cynodontia

Charassognathus Dvinia Procynosuchus Epicynodontia Cynosaurus Galesaurus Progalesaurus Nanictosaurus Thrinaxodon Platycraniellus Eucynodontia Cynognathia Probainognathia Lumkuia Ecteninion Aleodon Chiniquodon Probainognathus Trucidocynodon Therioherpeton Tritheledontidae Riograndia Chaliminia Elliotherium Diarthrognathus Pachygenelus Brasilodontidae Brasilitherium Brasilodon Tritylodontidae Oligokyphus Kayentatherium Tritylodon Beinotherium Mammaliaformes Sinoconodon Morganucodon

See also

• Evolution of mammals
• Prehistoric mammals
• List of prehistoric mammals

References

1. The slow and fast steps to becoming a mammal
2. 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.