Simbirskites inversum, from Ammoniten.org.

Belongs within: Perisphinctidae.
Contains: Olcostephaninae.

The Olcostephanidae are a lineage of ammonites known from the Upper Tithonian of the Upper Cretaceous to the Hauterivian of the Lower Cretaceous (Wright et al. 1996).

Characters (from Wright et al. 1996): Round-whorled to moderately compressed, normally with strong constrictions. Ribs typically bundled at umbilical tubercles, occasionally with single ribs. Inner whorls and dwarf genera may have lateral or ventrolateral tubercles. Strongly dimorphic; microconchs with long, spatulate lappets.

Olcostephanidae [Holcostephanidae]
    |--Spiticeratinae [Spiticeratidae]WCH96
    |    |--Proniceras Burckhardt 1919WCH96
    |    |    `--*P. pronus (Oppel 1865)WCH96 [=Ammonites pronusWCH96, Spiticeras (Proniceras) pronumP93]
    |    |--Umiaites Spath 1931WCH96
    |    |    `--*U. rajnathi Spath 1931WCH96
    |    |--Negreliceras Djanélidzé 1922 [incl. Praenegreliceras Collignon 1960 (n. n.)]WCH96
    |    |    `--*N. negreli (Matheron 1880) [=Ammonites negreli]WCH96
    |    |--Groebericeras Leanza 1945WCH96
    |    |    `--G. rocardi (Pomel 1889) [=Ammonites rocardi; incl. *G. bifrons Leanza 1945]WCH96
    |    |--Aspidostephanus Spath 1925WCH96
    |    |    `--*A. depressus (Steuer 1897) [=Holcostephanus depressus]WCH96
    |    `--Spiticeras Uhlig 1903 [incl. Somaliceras Spath 1925]WCH96
    |         |  i. s.: *Somaliceras’ isariforme Spath 1925WCH96
    |         |--S. (Spiticeras) [incl. Bihenduloceras Spath 1925]WCH96
    |         |    |--*S. (S.) spitiense (Blanford 1863) [=Ammonites spitiensis]WCH96
    |         |    `--S. (S.) gregoryi (Spath 1925) [=*Bihenduloceras gregoryi]WCH96
    |         `--S. (Kilianiceras Djanélidzé 1922)WCH96
    |              `--S. (*K.) damesi (Steuer 1897) [=Stephanoceras damesi]WCH96
    |  `--Holcodiscidae [Astieridiscidae, Metahoplitidae]WCH96
    |       |--Holcoptychites Gerth 1921WCH96
    |       |    `--*H. neuquensis (Douvillé 1910) [=Polyptychites neuquensis]WCH96
    |       |--Astieridiscus Kilian 1910WCH96
    |       |    `--*A. morleti (Kilian 1889) [=Holcodiscus morleti]WCH96
    |       |--Almohadites Wiedmann 1966WCH96
    |       |    `--*A. subcamelinus Wiedmann 1966WCH96
    |       |--Gymnoplites Spath 1933WCH96
    |       |    `--*G. simplex Spath 1933WCH96
    |       |--Parasaynoceras Breistroffer 1947 [incl. Neoastieria Obata & Matsukawa 1984 non Egoian 1969]WCH96
    |       |    |--*P. horridum (Orbigny 1850) [=Ammonites horridus]WCH96
    |       |    `--‘Astieria’ cadoceroides Karakasch 1907 [=*Neoastieria cadoceroides]WCH96
    |       |--Holcodiscus Uhlig 1882WCH96
    |       |    |--*H. caillaudianus (Orbigny 1850) [=Ammonites caillaudianus]WCH96
    |       |    |--H. intermediusP93
    |       |    `--H. kilianiR81
    |       `--Metahoplites Spath 1924WCH96
    |            |--*M. (Metahoplites) henoni (Coquand 1880) [=Ammonites henoni]WCH96
    |            `--M. (Medjeziceras Busnardo & David 1957)WCH96
    |                 `--M. (*M.) collignoni (Busnardo & David 1957) [=Spiticeras (*M.) collignoni]WCH96
    `--Simbirskites Pavlov 1892EK02 [Simbirskitidae, SimbirskitinaeWCH96]
         |  i. s.: S. broodiK79
         |         S. kleiniK79
         |         S. marginatusWCH96
         |         S. morvenae [incl. Perisphinctes kayseri Etheridge 1909 (preoc.)]F71
         |         S. progredicusK79
         |         S. variabilisR81
         |         S. versicolorWCH96
         |--S. (Simbirskites) (see below for synonymy)WCH96
         |    |--*S. (S.) decheni (Roemer 1841) [=Ammonites decheni]WCH96
         |    |--S. (S.) arminiusWCH96
         |    |--*Gorodzovia’ mosquitini Ivanov & Aristov 1969WCH96
         |    |--S. (S.) nodocinctusWCH96
         |    |--S. (S.) picteti (Weerth 1884) [=Ammonites picteti, *Thysanotoceras picteti]WCH96
         |    `--‘Ammonites’ traski Gabb 1864 [=*Californiceras traski]WCH96
         |--S. (Craspedodiscus Spath 1924) [incl. Hannoverites Kemper 1968 (n. n.)]WCH96
         |    |--S. (C.) discofalcatus (Lahusen 1874) (see below for synonymy)WCH96
         |    `--S. (C.) gottscheiK79
         |--S. (Hollisites Imlay 1957) [incl. Hertleinia Imlay 1957 non Marks 1949, Hertleinites Imlay 1958]WCH96
         |    |--S. (*H.) lucasi (Imlay 1957) [=*Hollisites lucasi]WCH96
         |    |--S. (H.) aguila (Anderson 1938) [=Neocraspedites aguila, *Hertleinia aguila, *Hertleinites aguila]WCH96
         |    `--S. (H.) dichotomusWCH96
         |--S. (Milanowskia Chernova 1952) [incl. Pavlovites Ivanov & Aristov 1969]WCH96
         |    |--S. (*M.) spetonensis (Young & Bird 1828) [=Ammonites spetonensis]WCH96
         |    |--S. (M.) ihmensisK79
         |    |--‘Speetoniceras’ polyptychoides Aristov 1967 [=*Pavlovites polyptychoides]WCH96
         |    `--S. (M.) staffi Wedekind 1915K79, EK02
         `--S. (Speetoniceras Spath 1924) [incl. Subspeetoniceras Ivanov & Aristov 1967]WCH96
              |--S. (*S.) subbipliciformis (Spath 1924) [=*Speetoniceras subbipliciforme]WCH96
              |--S. (S.) inverselobatusWCH96
              |--‘Speetoniceras’ inversioides Aristov 1967 [=*Subspeetoniceras inversioides]WCH96
              `--S. (S.) inversumWCH96

Simbirskites (Craspedodiscus) discofalcatus (Lahusen 1874) [=Ammonites discofalcatus; incl. A. clypeiformis Spath 1924 non Orbigny 1841, Simbirskites (*Craspedodiscus) clypeiformis, S. (C.) juddi Rawson 1971]WCH96

Simbirskites Pavlov 1892 (Simbirskites) [incl. Californiceras Shimizu 1931, Gorodzovia Ivanov & Aristov 1969, Thysanotoceras Whitehouse 1927]WCH96

*Type species of generic name indicated


[EK02] Engeser, T., & H. Keupp. 2002. Phylogeny of the aptychi-possessing Neoammonoidea (Aptychophora nov., Cephalopoda). Lethaia 35: 79–96.

[F71] Fletcher, H. O. 1971. Catalogue of type specimens of fossils in the Australian Museum, Sydney. Australian Museum Memoir 13: 1–167.

[K79] Kauffman, E. G. 1979. Cretaceous. In: Robison, R. A., & C. Teichert (eds) Treatise on Invertebrate Paleontology pt A. Introduction. Fossilisation (Taphonomy), Biogeography and Biostratigraphy pp. A418–A487. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

[P93] Page, K. N. 1993. Mollusca: Cephalopoda (Ammonoidea: Phylloceratina, Lytoceratina, Ammonitina and Ancyloceratina). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 213–227. Chapman & Hall: London.

[R81] Rawson, P. F. 1981. Early Cretaceous ammonite biostratigraphy and biogeography. In: House, M. R., & J. R. Senior (eds) The Ammonoidea: The evolution, classification, mode of life and geological usefulness of a major fossil group pp. 499–529. Academic Press.

[WCH96] Wright, C. W., J. H. Calloman & M. K. Howarth. 1996. Treatise on Invertebrate Paleontology pt L. Mollusca 4, revised vol. 4. Cretaceous Ammonoidea. The Geological Society of America, Inc.: Boulder (Colorado), and The University of Kansas: Lawrence (Kansas).

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