Medlicottioidea

The Lower Permian Akmilleria electraensis, from Zhou & Liengjarern (2004).

Belongs within: Ammonoidea.

The Medlicottioidea were a group of ammonoids that originated in the Lower Carboniferous and survived to the end of the Permian, with a single genus Episageceras crossing the Permian-Triassic boundary (McGowan & Smith 2007). The medlicottioids are characterised by the development of bidentition in the sutural lobes (Korn 2003). The trifid ventral lobe is narrower in members of the family Medlicottiidae than in the Pronoritidae.

<==Medlicottioidea
    |--Pronoritidae ZL04
    |    |  i. s.: Pronorites P68
    |    |           |--P. baconi P68
    |    |           |--P. cyclolobus [=Goniatites cyclolobus] H84
    |    |           |    |--P. c. cyclolobus P68
    |    |           |    `--P. c. arkansiensis Smith 1896 P68
    |    |           `--P. mixolobus H84
    |    |         Metapronorites RR79
    |    |         Sakmarites RR79
    |    `--Neopronoritinae ZL04
    |         |--Neopronorites Ruzhencev 1936 [incl. Epipronorites Maximowa 1938] ZL04
    |         |    |--*N. permicus (Tchernow 1907) [=Parapronorites permicus] ZL04
    |         |    `--N. darvasicus Leonova 1988 ZL04
    |         `--Parapronorites Gemmellaro 1887 ZL04
    |              |--*P. konincki Gemmellaro 1887 ZL04
    |              |--P. boesei Smith 1929 P68
    |              |--P. rectus Leonova 1989 ZL04
    |              `--P. timorensis Haniel 1915 ZL04
    `--Medlicottiidae ZL04
         |  i. s.: Medlicottia P68
         |           |--M. burckhardti P68
         |           |--M. copei White 1889 P68
         |           |--M. costellifera RR79
         |           |--M. girtyi Miller & Furnish 1940 P68
         |           |--M. malmquisti RR79
         |           |--M. orbignyianum [=Goniatites orbignyianus] H84
         |           |--M. primas H84
         |           `--M. whitneyi P68
         |         Neouddenites RR79
         |         Artioceras RR79
         |         Synartinskia RR79
         |         Artinskia RR79
         |           |--A. adkinsi P68
         |           |--A. kazakstanica RR79
         |           `--A. lilianae Miller & Youngquist 1947 P68
         |         Eumedlicottia RR79
         |           |--E. burckhardti RR79
         |           |--E. primas RR79
         |           `--E. whitneyi RR79
         |         Neogeoceras girtyi RR79
         |--Sicanites Gemmellaro 1887 [incl. Aktubinskia Ruzhencev 1947, Vanartinskia Ruzhencev 1978; Sicanitinae] ZL04
         |    |--*S. schopeni (Gemmellaro 1887) [=Medlicottia schopeni; incl. S. mojsisovicsi Gemmellaro 1887] ZL04
         |    `--S. notabilis (Ruzhencev 1940) [=Artinskia notabilis, Aktubinskia notabilis] ZL04
         `--Propinacoceratinae ZL04
              |--Propinacoceras Gemmellaro 1887 ZL04
              |    |--P. beyrichi RR79
              |    `--P. knighti Miller & Furnish 1940 P68
              |--Akmilleria Ruzhencev 1940 ZL04
              |    |--*A. transitorium (Haniel 1915) [=Propinacoceras transitorium] ZL04
              |    |--A. adkinsi (Plummer & Scott 1937) ZL04
              |    |--A. electraensis (Plummer & Scott 1937) [=Artinskia electraensis] ZL04
              |    `--A. huecoensis (Miller & Furnish 1940) ZL04
              `--Bamyaniceras Termier & Termier 1970 ZL04
                   |--*B. bouyxi Termier & Termier 1970 ZL04
                   |--B. australe (Teichert 1942) SLE01
                   |--B. loeiense (Ishibashi, Fujikawa & Nakornsri 1996) [=Artinskia loeiensis] ZL04
                   |--B. magnum Leonova 1992 ZL04
                   |--B. orientale Sone, Leman & Ehino 2001 SLE01
                   |--B. simile (Haniel 1915) SLE01
                   `--B. simplex Leonova 1989 ZL04

*Type species of generic name indicated

REFERENCES

[H84] Hyatt, A. 1883–1884. Genera of fossil cephalopods. Boston Soc. Nat. History, Proc. 22: 253-338.

Korn, D. 2003. Typostrophism in Palaeozoic ammonoids? Paläontologische Zeitschrift 77 (2): 445–470.

McGowan, A. J., & A. B. Smith. 2007. Ammonoids across the Permian/Triassic boundary: a cladistic perspective. Palaeontology 50 (3): 573–590.

[P68] Purnell, L. R. 1968. Catalog of the type specimens of invertebrate fossils. Part I: Paleozoic Cephalopoda. United States National Museum Bulletin 262: 1–198.

[RR79] Ross, C. A., & J. R. P. Ross. 1979. Permian. In: Robison, R. A., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt A. Introduction. Fossilisation (Taphonomy), Biogeography and Biostratigraphy pp. A291–A350. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

[SLE01] Sone, M., M. S. Leman & M. Ehino. 2001. Middle Permian cephalopods from central Peninsular Malaysia: implications for faunal migration through the southern Tethys. Journal of Asian Earth Sciences 19: 805–814.

[ZL04] Zhou, Z., & M. Liengjarern. 2004. Lower Permian perrinitid ammonoid faunas from Thailand. Journal of Paleontology 78: 317–339.