Mammaliaformes

 Left lower jaw of Shuotherium dongi, from Kielan-Jaworowska et al. (2002).

Belongs within: Probainognathia.
Contains: Haramiyida, Mammalia.

The Mammaliaformes has been defined as the most exclusive group containing both crown mammals and Sinoconodon, and represents the broader group of animals generally considered as ‘mammals’. Sinoconodon rigneyi is known from a partial skull from the lower Jurassic of China.

Synapomorphies (from Luo et al. 2002): Craniomandibular joint comprised of dentary condyle and squamosal glenoid; petrosal promontorium present; extensive development of a petrosal floor for the cavum epiptericum housing the trigeminal ganglion; separate tympanic aperture for prootic canal containing the prootic vein; fenestra vestibuli lacking thickened rim; hypoglossal foramen (cranial nerve XII) separated from the jugular foramen (cranial nerves IX, X, XI).

Mammaliaformes [Allotheria, Amphilestidae, Atheria, Eotheria, Triconodonta]
    |--Morganucodontidae [Morganucodonta]KH14
    |    |  i. s.: Brachyzostrodon Sigogneau-Russell 1983SM93
    |    |         Helvetiodon Clemens 1980SM93
    |    |         Wareolestes rex LK-Freeman 1979SM93
    |    |         IndotheriumLK-JC02
    |    |         Gondwanadon tapaniLK-JC02, DDL04
    |    |         IndozostrodonLK-JC02
    |    |         Erythrotherium parringtoniLK-JC02, CJ78
    |    |         Eozostrodon Parrington 1941D07
    |    |           `--E. parvusD07
    |    |--Megazostrodon Crompton & Jenkins 1968RW12, A02
    |    |    |--M. chenaliSK20
    |    |    `--M. rudneraeCJ78
    |    `--+--Dinnetherium Jenkins et al. 1983RW12, CM99
    |       |    `--D. nezorumH98
    |       `--Morganucodon Kühne 1949SK20, A02
    |            |--M. oehleriOB13 [=Eozostrodon oehleriCJ78]
    |            `--M. watsoni Kühne 1949S05 [=Eozostrodon watsoniCJ78]
    `--+--HaramiyidaSK20
       |--+--Hadrocodium Luo, Crompton & Sun 2001SK20, LCS01
       |  |    `--*H. wui Luo, Crompton & Sun 2001LCS01
       |  `--MammaliaSK20
       `--+--Woutersia Sigogneau-Russell 1983JL06, A02 [Woutersiidae]
          `--+--TikitheriumJL06
             `--DocodontaJL06
                  |  i. s.: Peraiocynodon inexpectatus Simpson 1928N10
                  |--+--TashkumyrodonJL06
                  |  `--TegotheriidaeN10
                  |       |--TegotheriumJL06
                  |       `--SibirotheriumJL06
                  `--DocodontidaeSM93
                       |  i. s.: DocofossorSK20
                       |         AgilodocodonSK20
                       |--+--Borealestes Waldman & Savage 1972JL06, SM93
                       |  `--+--Docodon Marsh 1881JL06, N10
                       |     `--Haldanodon Kühne & Krusat 1972SK20, SM93
                       |          `--H. exspectatusOB13
                       `--+--DsungarodonJL06
                          `--+--Castorocauda Ji, Luo et al. 2006BW14, JL06
                             |    `--*C. lutrasimilis Ji, Luo et al. 2006JL06
                             `--+--Simpsonodon Kermack 1987JL06, SM93
                                `--KrusatodonJL06
Mammaliaformes incertae sedis:
  Guchinodon Trofimov 1978SM93
  Tendagurodon Heinrich 1998H98
    `--*T. janenschi Heinrich 1998H98
  Staffia aenigmaticaBH05
  Kirtlingtonia Butler & Hooker 2005BH05
    `--*K. catenata Butler & Hooker 2005BH05
  MojoBH05
  HallautheriumBH05
  Theroteinus Sigogneau-Russell et al. 1986 [Theroteinida, Theroteinidae]SM93
  AllostaffiaBW14
  Avashishta bacharamensisBW14

*Type species of generic name indicated

References

[A02] Averianov, A. O. 2002. Early Cretaceous “symmetrodont” mammal Gobiotheriodon from Mongolia and the classification of “Symmetrodonta”. Acta Palaeontologica Polonica 47 (4): 705–716.

[BW14] Bi, S., Y. Wang, J. Guan, X. Sheng & J. Meng. 2014. Three new Jurassic euharamiyidan species reinforce early divergence of mammals. Nature 514: 579–584.

[BH05] Butler, P. M., & J. J. Hooker. 2005. New teeth of allotherian mammals from the English Bathonian, including the earliest multituberculates. Acta Palaeontologica Polonica 50: 185–207.

[CM99] Cifelli, R. L., & S. K. Madsen. 1999. Spalacotheriid symmetrodonts (Mammalia) from the medial Cretaceous (upper Albian or lower Cenomanian) Mussentuchit local fauna, Cedar Mountain Formation, Utah, USA. Geodiversitas 21 (2): 167–214.

[CJ78] Crompton, A. W., & F. A. Jenkins Jr. 1978. Mesozoic mammals. In: Maglio, V. J., & H. B. S. Cooke (eds) Evolution of African Mammals pp. 46–55. Harvard University Press: Cambridge (Massachusetts).

[DDL04] Datta, P. M., D. P. Das & Z.-X. Luo. 2004. A Late Triassic dromatheriid (Synapsida: Cynodontia) from India. Annals of Carnegie Museum 73 (2): 12–24.

[D07] Dixon, D. 2007. The Complete Illustrated Encyclopedia of Dinosaurs & Prehistoric Creatures. Hermes House: London.

[H98] Heinrich, W.-D. 1998. Late Jurassic mammals from Tendaguru, Tanzania, east Africa. Journal of Mammalian Evolution 5 (4): 269–290.

[JL06] Ji, Q., Z.-X. Luo, C.-X. Yuan & A. R. Tabrum. 2006. A swimming mammaliaform from the Middle Jurassic and ecomorphological diversification of early mammals. Science 311: 1123–1127.

[KH14] Krause, D. W., S. Hoffmann, J. R. Wible, E. C. Kirk, J. A. Schultz, W. von Koenigswald, J. R. Groenke, J. B. Rossie, P. M. O’Connor, E. R. Seiffert, E. R. Dumont, W. L. Holloway, R. R. Rogers, L. J. Rahantarisoa, A. D. Kemp & H. Andriamialison. 2014. First cranial remains of a gondwanatherian mammal reveal remarkable mosaicism. Nature 515: 512–517.

[LCS01] Luo, Z.-X., A. W. Crompton & A.-L. Sun. 2001. A new mammaliaform from the Early Jurassic and evolution of mammalian characteristics. Science 292: 1535–1540.

[LK-JC02] Luo, Z.-X., Z. Kielan-Jaworowska & R. L. Cifelli. 2002. In quest for a phylogeny of Mesozoic mammals. Acta Palaeontologica Polonica 47: 1–78.

[N10] Naish, D. 2010. Tetrapod Zoology: Book One. CFZ Press: Bideford (UK).

[OB13] O’Leary, M. A., J. I. Bloch, J. J. Flynn, T. J. Gaudin, A. Giallombardo, N. P. Giannini, S. L. Goldberg, B. P. Kraatz, Z.-X. Luo, J. Meng, X. Ni, M. J. Novacek, F. A. Perini, Z. S. Randall, G. W. Rougier, E. J. Sargis, M. T. Silcox, N. B. Simmons, M. Spaulding, P. M. Velazco, M. Weksler, J. R. Wible & A. L. Cirranello. 2013. The placental mammal ancestor and the post-K–Pg radiation of placentals. Science 339: 662–667.

[RW12] Rougier, G. W., J. R. Wible, R. M. D. Beck & S. Apesteguía. 2012. The Miocene mammal Necrolestes demonstrates the survival of Mesozoic nontherian lineage into the late Cenozoic of South America. Proceedings of the National Academy of Sciences of the USA 109 (49): 20053–20058.

[S05] Säilä, L. K. 2005. A new species of the sphenodontian reptile Clevosaurus from the Lower Jurassic of south Wales. Palaeontology 48 (4): 817–831.

[SM93] Stucky, R. K., & M. C. McKenna. 1993. Mammalia. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 739–771. Chapman & Hall: London.

[SK20] Sulej, T., G. Krzesiński, M. Tałanda, A. S. Wolniewicz, B. Błażejowski, N. Bonde, P. Gutowski, M. Sienkiewicz & G. Niedźwiedzki. 2020. The earliest-known mammaliaform fossil from Greenland sheds light on origin of mammals. Proceedings of the National Academy of Sciences of the USA 117 (43): 26861–26867.

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