Gastropods from the Lower Cretaceous of Vorarlberg, Austria. A ...
Gastropods from the Lower Cretaceous of Vorarlberg, Austria. A ...
Gastropods from the Lower Cretaceous of Vorarlberg, Austria. A ...
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KOLLMANN: <strong>Gastropods</strong> <strong>from</strong> <strong>the</strong> <strong>Lower</strong> <strong>Cretaceous</strong> <strong>of</strong> <strong>Vorarlberg</strong>. A systematic review 41<br />
Material: Reference material to HEIM, BAUMBERGER & FUSSENEGGER : 1 fragment <strong>from</strong><br />
Gopf, Bregenzer Ach close to Mellau (VN: P 11460)<br />
Description. Fragment <strong>of</strong> a moderately high, small spire. Whorls gradate, adapically<br />
with broad, inclined ramp delimited by obtuse angulation. Abapical whorl face strongly<br />
inclined, slightly concave, becoming almost parallel to shell axis with ontogeny.<br />
Indistinct traces <strong>of</strong> spiral ribs.<br />
Remarks. The specimen does not possess a selenizone and <strong>the</strong>refore does not belong to<br />
Pleurotomariidae. The gradate whorls agree with Turbo thurmanni PICTET &<br />
CAMPICHE,1862, p. 482, pl. 86, fig. 4-5, which is <strong>the</strong> type species <strong>of</strong> Helicacanthus<br />
COSSMANN. A specific determination <strong>of</strong> <strong>the</strong> fragment is not possible.<br />
Distribution in <strong>Vorarlberg</strong>. Garschella Formation<br />
Suborder NERITIMORPHA<br />
Superfamily NERITOIDEA<br />
Family Neritidae<br />
Subfamily Neritinae<br />
Genus Neritoma MORRIS, 1849<br />
Genus Neridomus MORRIS & LYCETT, 1851<br />
Neritoma (Neridomus) dolichostoma (COSSMANN)<br />
Plate 4 Figure 46, 47<br />
1907 Neritodomus dolichostoma COSSMANN, p. 24, pl. 6, fig. 18-20<br />
Material. 1 specimen, ?Unterklien (GBA: 2002/002/007)<br />
Dimensions. H: 1.2 mm; B: 1.2 mm<br />
Description. Small, globular and thick-shelled shells; Whorls smooth, almost completely<br />
overlapping earlier ones. Suture slightly grooved in <strong>the</strong> final portion <strong>of</strong> <strong>the</strong> last whorl.<br />
Aperture broad, flaring, with broad, smooth septum.<br />
Remarks. Cossmann, 1918, p. 385, fig. 22, has documented <strong>the</strong> specimen besides <strong>the</strong><br />
original description. Only a small number <strong>of</strong> morphological characters are relevant for<br />
distinguishing Neridomus species. The species <strong>from</strong> <strong>Vorarlberg</strong> is assigned to N.<br />
dolichostoma because <strong>of</strong> <strong>the</strong> equally oviform shell.<br />
Distribution. Urgonian facies, South France<br />
Distribution in <strong>Vorarlberg</strong>. Schrattenkalk Formation<br />
1879 Nerita bicostata VACEK, p. 750, pl. 16, fig. 6<br />
Genus Otostoma D´ARCHIAC, 1859<br />
Otostoma bicostata (VACEK)<br />
Plate 4 figures 48, 49
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