Coelostylinidae

Coelostylina ahlburgi, from Tong & Erwin (2001).

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 TE01
    |--Turriculina Gregorio 1930 P66
    |    `--*T. unica Gregorio 1930 P66
    |--Kittlistylus Haas 1953 TE01
    |    `--*K. flexuosus [=Turritella flexuosa, Eustylus flexuosus] TE01
    |--Gradiella Kittl 1899 TE01
    |    |--*G. gradata (Hörnes 1856) [=Chemnitzia gradata] TE01
    |    `--G. semigradata TE01
    |--Coelostylina Kittl 1894 BR05
    |    |--*C. conica (Münster 1841) [=Melania conica] TE01
    |    |--C. ahlburgi (Assmann 1924) [=Omphaloptycha ahlburgi; incl. O. ecki Assmann 1924] TE01
    |    |--C. irritata TE01
    |    `--C. waageni Kittl 1894 TE01
    |--Toxoconcha Kittl 1899 TE01
    |    |--*T. brocchii (Stoppani 1858-1860) [=Chemnitzia brocchii] TE01
    |    |    |--T. b. brocchii TE01
    |    |    `--T. b. brevis TE01
    |    `--T. uniformis (Stoppani 1858) [=Chemnitzia uniformis, Undularia (Toxoconcha) uniformis] TE01
    |--Omphaloptycha Ammon 1892 TE01
    |    |--*O. nota (Ammon 1878) [=Chemnitzia nota] TE01
    |    |--O. cochlea TE01
    |    |--O. gansuensis Tong & Erwin 2001 TE01
    |    `--O. jaworskii [incl. Phasianella muensteri] TE01
    `--Trypanostylus Cossmann 1895 TE01
         |--*T. militaris (Kittl 1894) [=Eustylus militaris] TE01
         |--T. konincki (Münster 1841) (see below for synonymy) TE01
         |--T. pseudoscalatus Assmann 1924 TE01
         `--T. semiglaber TE01

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

[BR05] Bouchet, P., J.-P. Rocroi, J. Frýda, B. Hausdorf, W. Ponder, Á. Valdés & A. Warén. 2005. Classification and nomenclator of gastropod families. Malacologia 47 (1-2): 1-397.

[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, pl. 1-23.

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

Wenz, W. 1938-1944. Gastropoda. Teil 1: Allgemeiner Teil und Prosobranchia. In: Schindewolf, O.H. (ed) Handbuch der Paläozoologie vol. 6, pp. 1-231. Gebrüer Bornträger: Berlin.