Coelostylinidae

Belongs within: Hypsogastropoda.

Coelostylinidae is a family of high-spired Mesozoic gastropods of uncertain affinities, probably related to the Hypsogastropoda (‘littorinimorphs’, ‘ptenoglossans’ and neogastropods). It is quite possible that this ‘family’ represents a poly-/paraphyletic assemblage of stem taxa of other hypsogastropods.

Characteristics (from Wenz 1938–1944):

Gehäuse mehr oder weniger getürmt kegelförmig; Achse in der ganzen Länge hohl und daher meist mehr oder weniger deutlich offen genabelt; der Nabel von einer Kante begrenzt; Anfangswindungen bisweilen etwas gegen die Achse geneigt; Umgänge mit mehr oder weniger deutlich [reverse S]-förmig gebogenen bis fast gestreckten, meist etwas schiefen Anwachsstreifen; Mündung ganzrandig, unten meist gewinkelt oder leicht schnabelartig; Außenrand etwas vorgezogen.

Despite not being proficient in German, I’ve been able to decipher part of the above using Google Translate: “More or less high cone-shaped shell; umbilicus bounded by an edge, initial whorls sometimes slightly inclined to the axis, whorls more or less clearly [reverse S]-shaped to almost elongated; aperture entire, mostly angled or slightly beak-like ventrally; outer edge slightly forward.”

<==Coelostylinidae [Coelostylinoidea]
    |--‘Eustylus’ Kittl 1894 non Schönh. 1843TE01
    |--Undularia Koken 1892B91
    |--Turriculina Gregorio 1930P66
    |    `--*T. unica Gregorio 1930P66
    |--Kittlistylus Haas 1953TE01
    |    `--*K. flexuosus [=Turritella flexuosa, Eustylus flexuosus]TE01
    |--Gradiella Kittl 1899TE01
    |    |--*G. gradata (Hörnes 1856) [=Chemnitzia gradata]TE01
    |    `--G. semigradataTE01
    |--Toxoconcha Kittl 1899TE01
    |    |--*T. brocchii (Stoppani 1858–1860) [=Chemnitzia brocchii]TE01
    |    |    |--T. b. brocchiiTE01
    |    |    `--T. b. brevisTE01
    |    `--T. uniformis (Stoppani 1860)NE02 [=Chemnitzia uniformisTE01, Undularia (Toxoconcha) uniformisTE01]
    |--Trypanostylus Cossmann 1895TE01
    |    |--*T. militaris (Kittl 1894) [=Eustylus militaris]TE01
    |    |--T. konincki (Münster 1841) (see below for synonymy)TE01
    |    |--T. pseudoscalatus Assmann 1924TE01
    |    `--T. semiglaberTE01
    |--Coelostylina Kittl 1894BR05
    |    |--*C. ‘conica’ (Münster 1841) [=Melania conica non Gray 1833]TE01
    |    |--C. ahlburgi (Assmann 1924) [=Omphaloptycha ahlburgi; incl. O. ecki Assmann 1924]TE01
    |    |--C. costata Batten & Stokes 1986NE02
    |    |--C. irritataTE01
    |    |--C. virginensis Batten & Stokes 1986NE02
    |    |--C. waageni Kittl 1894TE01
    |    `--C. werfensis Wittenburg 1908NE02
    `--Omphaloptychia Ammon 1893TE01, NE02
         |--*O. nota (Ammon 1878) [=Chemnitzia nota]TE01
         |--O. cingulata Batten 1985TTE93
         |--O. cochleaTE01
         |--O. gansuensis Tong & Erwin 2001TE01
         |--O. hormolira Batten & Stokes 1986NE02
         |--O. jaworskii [incl. Phasianella muensteri]TE01
         |--O. laticonvexa Wang in Wang & Xi 1980NE02
         |--O. paleozoica Batten 1985TTE93
         |--O. permianaG31
         `--O. schmidti Assmann 1924NE02

Trypanostylus konincki (Münster 1841) [=Melania koninekeana, Eustylus konincki, M. konninkeanu (l. c.); incl. M. longissima Münster 1841]^TE01

*Type species of generic name indicated

References

[B91] Bandel, K. 1991. Über triassische “Loxonematoidea” und ihre Beziehungen zu rezenten und paläozoischen Schnecken. Paläontologische Zeitschrift 65 (3–4): 239–268.

[BR05] Bouchet, P., & J.-P. Rocroi. 2005. Classification and nomenclator of gastropod families. Malacologia 47 (1–2): 1–397.

[G31] Grabau, A. W. 1931. The Permian of Mongolia: A report on the Permian fauna of the Jisu Honguer limestone of Mongolia and its relations to the Permian of other parts of the world. American Museum of Natural History: New York.

[NE02] Nützel, A., & D. H. Erwin. 2002. Battenizyga, a new Early Triassic gastropod genus with a discussion of the caenogastropod evolution at the Permian/Triassic boundary. Paläontologische Zeitschrift 76 (1): 21–27.

[P66] Powell, A. W. B. 1966. The molluscan families Speightiidae and Turridae: an evaluation of the valid taxa, both Recent and fossil, with lists of characteristic species. Bulletin of the Auckland Institute and Museum 5: 1–184, pls 1–23.

[TE01] Tong, J., & D. H. Erwin. 2001. Triassic gastropods of the southern Qinling Mountains, China. Smithsonian Contributions to Paleobiology 92: 1–47.

[TTE93] Tracey, S., J. A. Todd & D. H. Erwin. 1993. Mollusca: Gastropoda. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 131–167. Chapman & Hall: London.