Australiceras sp., in the Houston Museum of Natural Science.

Belongs within: Stephanocerataceae.
Contains: Ancyloceras, Heteroceratidae, Deshayesitidae, Parahoplitidae, Tropaeum.

The Ancyloceratidae are a group of ammonites known from the Lower Cretaceous. They are commonly heteromorphic, though some derived forms reverted to a more standard tight coil.

Characters (from Wright et al. 1996): Either coiled in a loose or tight, more or less equiangular spiral (criocone) or with an initial spire followed by curved or straight shaft and terminal hook (ancyloceratoid); sometimes with phylogenetic tendency to tighter, normal ammonitic coiling. Whorl section ranging from circular to square or polygonal; tending to develop strong, periodic ribs with umbilical, lateral, and ventrolateral spines, separated by few to many, fine, untuberculate ribs. Ornament rarely constant through growth. Probably strongly dimorphic throughout, but presumed microconchs rarely matched with macroconchs. Sutures florid, with trifid lobes or simplifying.

    |    |--Leptoceratoides Thieuloy 1966WCH96
    |    |    `--*L. pumilum (Uhlig 1883) [=Crioceras (Leptoceras) pumilum] Uhlig 1883WCH96
    |    |--Karsteniceras Royo y Gomez 1945WCH96
    |    |    `--*K. beyrichi (Karsten 1858) [=Ancyloceras beyrichi]WCH96
    |    |--Orbignyceras Royo y Gomez 1945WCH96
    |    |    `--*O. veleziense Royo y Gomez 1945 [=*Veleziceras veleziense]WCH96
    |    `--Hamulinites Paquier 1900 (see below for synonymy)WCH96
    |         |--*H. munieri (Nicklès 1894)WCH96 (see below for synonymy)
    |         |--‘Crioceras (Leptoceras)’ assimile Uhlig 1883 [=*Tzankoviceras assimile]WCH96
    |         `--H. parvulum (Uhlig 1883) [=Crioceras (Leptoceras) parvulum, *Eoleptoceras parvulum]WCH96
    |--Helicancylinae [Epacrioceratidae, Helicancylidae, Protacrioceratide]WCH96
    |    |--Lytocrioceras Spath 1924WCH96
    |    |    `--*L. jauberti (Astier 1851) [=Ancyloceras jauberti]WCH96
    |    |--Luppovia Bogdanova, Kakabadze & Mikhailova in Kakabadze, Bogdanova & Mikhailova 1978WCH96
    |    |    `--*L. dostshanensis Bogdanova, Kakabadze & Mikhailova in Kakabadze, Bogdanova & Mikhailova 1978WCH96
    |    |--Epanisoceras Collignon 1962WCH96
    |    |    `--*E. raulinianiforme (Breistroffer in Collignon 1937) [=Protanisoceras raulinianiforme]WCH96
    |    |--Toxoceratoides Spath 1924WCH96
    |    |    |--*T. royerianum (Orbigny 1842) [=Toxoceras royerianum]WCH96
    |    |    `--T. taylori (Etheridge 1892) [=Ancyloceras taylori]F71
    |    |--Tonohamites Spath 1924 [incl. Colomboceratoides Etayo Serna 1979]WCH96
    |    |    |--*T. decurrens Spath 1924WCH96 [=Hamites decurrensO93]
    |    |    `--‘Toxoceratoides (*Colomboceratoides)’ renzoni Etayo Serna 1979WCH96
    |    |--Helicancylus Gabb 1869WCH96
    |    |    |--*H. aequicostatum (Gabb 1864) [=Ptychoceras aequicostatum, Hamiticeras aequicostatum]WCH96
    |    |    |--H. gabbiWCH96
    |    |    |--H. patagonicumRC02
    |    |    `--H. pilsburyi (Anderson 1938) [=*Hamiticeras pilsburyi]WCH96
    |    |--Hoplocrioceras Spath 1924 [incl. Aspinoceras Anderson 1938, Subaspinoceras Thomel, Delanoy & Autran 1987]WCH96
    |    |    |--*H. phillipsi (Phillips 1829) [=Hamites phillipsi]WCH96
    |    |    |--H. dilatatumWCH96
    |    |    |--H. fissicostatumR81
    |    |    |--*Aspinoceras’ hamlini Anderson 1938WCH96
    |    |    |--‘Ancyloceras’ mulsanti Astier 1851 [=*Subaspinoceras mulsanti]WCH96
    |    |    `--H. rarocinctumR81
    |    `--Acrioceras Hyatt 1900 [incl. Mesocrioceras Breistroffer 1951 (n. n.)]WCH96
    |         |--*A. (Acrioceras) tabarelli (Astier 1851) [=Ancyloceras tabarelli]WCH96
    |         |--A. (Dissimilites Sarkar 1954)WCH96
    |         |    `--A. (*D.) dissimilis (Orbigny 1842) [=Hamites dissimilis]WCH96
    |         |--A. (Epacrioceras Egoian 1974)WCH96
    |         |    `--A. (*E.) rarum (Egoian 1974) [=*Epacrioceras rarum]WCH96
    |         |--A. (Paraspinoceras Sarkar 1955)WCH96
    |         |    `--A. (*P.) pulcherrimum (Orbigny 1842) [=Ancyloceras pulcherrimum]WCH96
    |         `--A. (Protacrioceras Sarkar 1955)WCH96
    |              `--A. (*P.) ornatum (Orbigny 1850) [=Ancyloceras ornatum]WCH96
         |  i. s.: Moutoniceras Sarkar 1954WCH96
         |           |--*M. moutonianum (Orbigny 1850) [=Toxoceras moutonianum]WCH96
         |           `--M. annulareP93
         |         Acanthoptychoceras Manolov 1962 (n. d.)WCH96
         |           `--*A. spinatocostatum Manolov 1962 (n. d.)WCH96
         |         Shastoceras Anderson 1938WCH96
         |           `--*S. californicum Anderson 1938WCH96
         |         Peltocrioceras Spath 1924WCH96
         |           `--*P. deeckei (Favre 1908) [=Crioceras deeckei]WCH96
         |         Pseudoaustraliceras Kakabadze 1981WCH96
         |           `--*P. ramososeptatum (Anthula 1899) [=Crioceras ramososeptatum]WCH96
         |         Helicancyloceras Klinger & Kennedy 1977 [incl. Nonyaniceras Klinger & Kennedy 1977]WCH96
         |           |--*H. vohimaranitraense (Collignon 1962) [=Heteroceras (Argvethites) vohimaranitraense]WCH96
         |           `--H. nonyani Klinger & Kennedy 1977 [=H. (*Nonyaniceras) nonyani]WCH96
         |         Caspianites Casey 1961WCH96
         |           `--*C. wassiliewskyi (Renngarten 1926) [=Crioceras (Ammonitoceras) wassiliewskyi]WCH96
         |         Antarcticoceras Thomson 1974WCH96
         |           `--*A. antarcticum Thomson 1974WCH96
         |         Huastecoceras Cantu-Chapa 1976WCH96
         |           `--*H. trispinosoides (Burckhardt 1925) [=Crioceras trispinosoides]WCH96
         |--Lithancylus Casey 1960W69, WCH96
         |    |--*L. grandis (Sowerby 1828) [=Hamites grandis]WCH96
         |    `--L. tirolensisWCH96
            |  `--DeshayesitaceaeWCH96
            |       |--DeshayesitidaeWCH96
            |       `--ParahoplitidaeWCH96
            |--+--Epancyloceras Spath 1930W69, WCH96
            |  |    `--*E. hythense Spath 1930WCH96
            |  `--Ammonitoceras Dumas 1876W69, WCH96
            |       |--*A. ucetiae Dumas 1876WCH96
            |       |--A. lahuseniWCH96
            |       |--A. sowerbyiP93
            |       `--A. tovilenseW69
               `--Australiceras Whitehouse 1926W69, WCH96 (see below for synonymy)
                    |  i. s.: *Colombiaticeras’ bolicari Royo y Gomez 1945WCH96
                    |         A. gracileF71
                    |         A. irregulare [=Crioceras irregulare]F71
                    |         A. lampros (Etheridge 1909) [=Crioceras lampros]F71
                    |         A. robustum Whitehouse 1926F71
                    |--A. gigas (Sowerby 1828)W69, WCH96 [=Hamites gigasWCH96, *Proaustraliceras gigasWCH96]
                    `--+--*A. jacki (Etheridge 1880)WCH96, W69, WCH96 [=Crioceras jackiWCH96; incl. Tropaeum undatumF71]
                       `--A. tuberculatumW69

Australiceras Whitehouse 1926W69, WCH96 [incl. Colombiaticeras Royo y Gomez 1945WCH96, Proaustraliceras Kakabadze 1977WCH96]

Hamulinites Paquier 1900 [=Wrightites Manolov 1962; incl. Eoleptoceras Manolov 1962, Tzankoviceras Manolov 1962]WCH96

*Hamulinites munieri (Nicklès 1894)WCH96 [=Hamulina munieriWCH96, Leptoceras (Hamulinites) munieriWK81, *Wrightites munieriWCH96]

*Type species of generic name indicated


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

[O93] Ohkubo, N. 1993. A new species of Graptoppia (Acari: Oribatei) from Japan. Edaphologia 49: 11–16.

[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.

[RC02] Riding, J. B., & J. A. Crame. 2002. Aptian to Coniacian (Early–Late Cretaceous) palynostratigraphy of the Gustav Group, James Ross Basin, Antarctica. Cretaceous Research 23: 739–760.

[W69] Wiedmann, J. 1969. The heteromorphs and ammonoid extinction. Biological Reviews 44: 563–602.

[WK81] Wiedmann, J., & J. Kullmann. 1981. Ammonoid sutures in ontogeny and phylogeny. 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. 215–255. 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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