Endoplocus inflatus, Gründel & Keupp & Lang & Nützel, 2022

Gruendel, Joachim, Keupp, Helmut, Lang, Fritz & Nuetzel, Alexander, 2022, Late Jurassic (Upper Kimmeridgian) Heterobranchia (Gastropoda) of the coral-facies of Saal near Kelheim and the viciniy of Nattheim (Germany), Zitteliana 96, pp. 179-221 : 179

Endoplocus inflatus sp. nov.

Plate 8: figs 1-4

Etymology.

Latin Endoplocus inflatus - inflated, according to the inflated last whorls of large specimens.

Holotype.

SNSB-BSPG 2021 XV 20, Lang collection.

Locus typicus.

Saal Quarry near Kelheim.

Stratum typicum.

Upper Kimmeridgian.

Paratypes.

Seven specimens from Saal, collections Lang and Keupp: SNSB-BSPG 2021 XV 21, 22, 108, 179-182.

Additional material.

Two specimens from Saal, without type status (one specimen collection Neubauer, one specimen collection Lang).

Diagnosis.

Spire conical, acute, coeloconoid, consisting of numerous whorls with low whorl face; last whorl of larger specimens inflated with convex whorl face; nodes absent.

Description.

The holotype is 15 mm high. The early teleoconch is conical, acute, coeloconoid, slender, and consists of numerous very low whorls. A relatively well-preserved juvenile paratype (Plate 8 : fig. 4) has a flat ramp demarcated by a distinct angulation. Later whorls increase more rapidly in width producing coeloconoid shape. The last part of the last whorl is deflected downward so that the height of the whorl increases more rapidly. The transition from whorl face to the strongly convex base is evenly rounded. The last whorl is strongly convex and somewhat inflated. The shell is smooth, except in rare cases (due to preservation?) with a narrow subsutural spiral furrow. The base is narrowly phaneromphalous. The aperture is strongly damaged in all specimens; it has a strong parietal plait and two columellar plaits (adapical one weaker).

Relationships.

Phaneroptyxis proboscidea Cossmann, 1898 has an even more inflated last whorl and is ornamented with nodes. Phaneroptyxis cf. nogreti (Guirand and Ogérien) sensu Hägele (1997) has fewer and higher whorls, a narrow ramp that accentuates the sutures, and its last whorl is not inflated. Phaneroptyxis obtusiceps Zittel sensu Hakobjan (1962) has a nodular ornament. Endoplocus staczycii (Zeuschner) sensu Wieczorek (1998) is similar but is slenderer, its last whorl is not as inflated, and its whorls are higher. According to Wieczorek (1998) this species is very variable. Nerinea clymene d’Orbigny sensu Gemmellaro (1870: pl. 4, fig. 3, non figs 4, 5) has a higher and less inflated last whorl and higher spire whorls.

Figures

Plate 8. Endoplocus inflatus sp. nov. (1 - 3) Holotype, SNSB-BSPG 2021 XV 20, Saal (collection Lang); (1) lateral view, height 16 mm; (2) aperture, height 6.5 mm; (3) base, width 9 mm. (4) Paratype, SNSB-BSPG 2021 XV 108, Saal (collection Lang), juvenile specimen showing ramp on early whorls, height 9 mm.