Diagnoza

The shell is highly trochiform; flanks are of greatest width just above the abapical coil; apex is flattened; first two coils are only slightly trochospiral; spiral rib formed on the first teleoconch coil, which lies roughly in the middle of the second coil and just above the abapical suture on the third one; adult specimens are of very different in size (8.5 to 17 mm hight); spiral ribs are humped; weak prosocline axial ribs run from suture to suture connecting the cusps; the aperture is round.

Porównanie

Belongs to a group of similar species that was widespread at least in the period from the Bajocian to the Oxfordian (Turbo cassius d'Orbigny, 1850; T. davoustii d'Orbigny, 1851; T. hamptonensis Morris & Lycett, 1851; T. planispira Cossmann, 1885 ; T. ferretensis Andreae, 1887; Monodonta lyelli d'Archiac).

Autekologia

Występowanie geograficzne

France, in Poland only in the Kłęby borehole.

Zasięg czasowy

Mid Jurassic(mid Callovian)

Materiały muzealne

26 specimens (5 specimens from Poland).

Literatura

Couffon, O. 1919. Le Callovien du Chalet, commune de Montreuil-Bellay, 245 pp. G. Grassin, Angers.

Gründel, J. 1990. Gastropoden aus Callov-Geschieben aus dem nordosten  Deutschlands. II. Mathildidae, Trochacea, Palaeotrochacea, Amberleyacea,  Rissoinidae,  Pleurotomariidae und Purpurinidae. Zeitschrift  für geologische  Wissenschaften, 18: 1137–1151.

Gründel, J. 2000. Archaeogastropoda aus dem Dogger Norddeutschlands und des nordwestlichen Polens. Berliner geowissenschaftliche Abhandlungen, Reihe E, 34: 205–253.

Gründel, J. 2009. Zur Kenntnis der Gattung Metriomphalus Cossmann, 1916 (Gastropoda, Vetigastropoda). Zitteliana, Series A 48/49: 39‒49.

Hébert,  M. & Eudes-Deslongchamps,  E. 1860. Mémoire sur les fossiles de Montreuil-Bellay (Maine-et-Loire), 1re partie. Céphalopodes et Gastéropodes. Bulletin de le Société Linnéenne  de Normandie, 5: 153–240