Simpsonodon Temporal range: Bathonian-Callovian ~165–162 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Clade:	Therapsida
Clade:	Cynodontia
Clade:	Mammaliaformes
Order:	†Docodonta
Genus:	†Simpsonodon Kermack et al, 1987
Type species
†Simpsonodon oxfordensis Kermack et al, 1987
Other species
†S. sibiricus (Averianov et al, 2010)

Simpsonodon is an extinct genus of docodontan mammaliaform known from the Middle Jurassic of England, Kyrgyzstan and Russia. The type species S. oxfordensis was described from the Kirtlington Mammal Bed and Watton Cliff in the Forest Marble Formation of England. It was named after George Gaylord Simpson, a pioneering mammalologist and contributor to the Modern Evolutionary Synthesis.^[1] A second species S. sibiricus is known from the Itat Formation of Russia,^[2] and indeterminate species of the genus are also known from the Balabansai Formation in Kyrgyzstan^[3]

References

^ KERMACK, K. A.; LEE, A. J.; LEES, PATRICIA M.; MUSSETT, FRANCES (January 1987). "A new docodont from the Forest Marble". Zoological Journal of the Linnean Society. 89 (1): 1–39. doi:10.1111/j.1096-3642.1987.tb01342.x. ISSN 0024-4082.
^ Averianov, A. A.; Lopatin, A. V.; Krasnolutskii, S. A.; Ivantsov, S. V. (2010). "New docodontians from the Middle Jurassic of Siberia and reanalysis of docodonta interrelationships" (PDF). Proceedings of the Zoological Institute RAS. 314 (2): 121–148. doi:10.31610/trudyzin/2010.314.2.121. S2CID 35820076.
^ Martin, Thomas; Averianov, Alexander O. (2010-05-18). "Mammals from the Middle Jurassic Balabansai Formation of the Fergana Depression, Kyrgyzstan". Journal of Vertebrate Paleontology. 30 (3): 855–871. doi:10.1080/02724631003758045. ISSN 0272-4634. S2CID 128716878.

see Synapsida
Cynodontia	see below↓

†Dvinia †Nanocynodon †Madysaurus †Uralocynodon
†Charassognathidae	Abdalodon Charassognathus Nshimbodon
†Procynosuchidae	Procynosuchus Sludica

†Agudotherium †Candelariodon †Charruodon †Lumkuia †Protheriodon †Tessellatia
†Chiniquodontidae	Aleodon Chiniquodon Cromptodon? Riojanodon
†Probainognathidae	Bonacynodon Probainognathus
†Ecteniniidae	Diegocanis Ecteninion Trucidocynodon

†Adelobasileus †Botucaraitherium †Brasilodon †Sinoconodon †Tikiodon
†Tritylodontidae	Bienotherium Bienotheroides Bocatherium Dianzhongia Dinnebitodon Fossiomanus Kayentatherium Lufengia Montirictus Nuurtherium Oligokyphus Polistodon Shartegodon Stereognathus Tritylodon Xenocretosuchus Yuanotherium Yunnanodon
Mammaliaformes	see below↓

Allostaffia? Arboroharamiya Baidabatyr? Butlerodon Cryoharamiya Kermackodon? Maiopatagium Megaconus? Qishou Sharypovoia Shenshou Sineleutherus Vilevolodon Woodeatonia Xianshou Gondwanatheria?
Hahnodontidae?	Cifelliodon Denisodon Hahnodon

Incertae sedis
†Eoraetia †Gaumia †"Hahnia" †Kunminia †Lepagia †Meurthodon †Mitredon †Panchetocynodon †Redondagnathus