Cynognathia

Cynognathians Temporal range: Early to Late Triassic, 251–208.5 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Skull of the carnivorous cynognathian Cynognathus crateronotus
Skull of Exaeretodon a herbivorous traversodontid
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Clade:	Therapsida
Clade:	Cynodontia
Clade:	Eucynodontia
Clade:	†Cynognathia Hopson and Barghusen, 1986
Subgroups
†Cynognathus †Gomphodontia †Diademodontidae †Neogomphodontia Hendrickx et al., 2020[1] †Trirachodontidae †Traversodontidae

Cynognathia ("dog jaw") is one of two major clades of cynodonts, the other being Probainognathia. Cynognathians included the large carnivorous genus Cynognathus and the herbivorous or omnivorous gomphodonts such as traversodontids. Cynognathians can be identified by several synapomorphies including a very deep zygomatic arch that extends above the middle of the orbit.

Cynognathian fossils are currently known from Africa, Antarctica, Asia, Europe, North America and South America.

Taxonomy

• Suborder Cynodontia
  • Infraorder Eucynodontia
    • (unranked) Cynognathia
      • Family Cynognathidae
        • Cynognathus
      • (unranked) Gomphodontia
        • Family Diademodontidae
          • Diademodon
          • Titanogomphodon
        • (unranked) Neogomphodontia
          • Family Trirachodontidae
            • Subfamily Trirachodontinae
              • Langbergia
              • Trirachodon
            • Subfamily Sinognathinae
              • Beishanodon
              • Sinognathus
              • Cricodon
          • Family Traversodontidae
            • Etjoia
            • Nanogomphodon
            • Scalenodon
            • Subfamily Traversodontinae
              • Traversodon
              • Luangwa
            • Unnamed clade
              • Andescynodon
              • Pascualgnathus
              • Mandagomphodon
              • Subfamily Massetognathinae
                • Dadadon
                • Massetognathus
                • Santacruzodon
              • Subfamily Arctotraversodontinae
                • Arctotraversodon
                • Boreogomphodon
                • Plinthogomphodon
                • Habayia
                • Maubeugia
                • Microscalenodon
                • Mandagomphodon
                • Rosieria
              • Subfamily Gomphodontosuchinae
                • Gomphodontosuchus
                • Menadon
                • Protuberum
                • Ruberodon
                • Scalenodontoides
                • Exaeretodon
                • Siriusgnathus

Phylogeny

Cynognathians in a cladogram after Stefanello et al. (2023):^[2]

Eucynodontia	Cynognathia Cynognathus crateronotus Gomphodontia Diademodon tetragonus Langbergia modisei Trirachodon berryi Sinognathus gracilis Traversodontidae Pascualgnathus polanskii Luangwa drysdalli Scalenodon angustifrons Mandagomphodon hirschoni Massetognathus pascuali Exaeretodon argentinus Probainognathia

See also

• Evolution of mammals

References

1. Hendrickx, C.; Gaetano, L. C.; Choiniere, J. N.; Mocke, H.; Abdala, F. (2020). "A new traversodontid cynodont with a peculiar postcanine dentition from the Middle/Late Triassic of Namibia and dental evolution in basal gomphodonts". Journal of Systematic Palaeontology. 18 (20): 1669–1706. doi:10.1080/14772019.2020.1804470. S2CID 221838726.
2. Stefanello, M.; Martinelli, A. G.; Müller, R. T.; Dias-da-Silva, S.; Kerber, L. (2023). "A complete skull of a stem mammal from the Late Triassic of Brazil illuminates the early evolution of prozostrodontian cynodonts". Journal of Mammalian Evolution. 30 (2): 299–317. doi:10.1007/s10914-022-09648-y. S2CID 256452176.