Volvocylindrites marcousana (Guirand & Ogerien , 1865)

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

Volvocylindrites marcousana (Guirand & Ogerien, 1865)

Plate 21: figs 3-5

*1865 - Bulla marcousana sp. nov. - Guirand and Ogérien: 388, figs 40, 41.

1872 - Volvula marcousana Guirand et Ogérien - Loriol in Loriol, Royer and Tombeck: 72, pl. 5, fig. 8.

1886-1888 - Volvula marcousana Guirand et Ogérien - Loriol in Loriol and Bourgeat: 53, pl. 3, figs 6-9.

1893 - Volvula marcousana Guirand et Ogérien - Loriol in Loriol and Lambert: 13, pl. 1, fig. 4.

1895 - Volvocylindrites marcousanus Guir. et Ogér. - Cossmann: 87, pl. 4, fig. 14.

1927 - Cylindrites extensus nov. sp. - Maire: 122, pl. 6, figs 55-57.

2012 - Volvocylindrites marcousana (Guirand and Ogérien) - Gründel and Nützel: 37, fig. 3g-h.

Material.

Thirty-nine mostly juvenile specimens from Saal, collection Lang, SNSB-BSPG 2021 XV 99, 100.

Description.

The largest specimen is 12 mm high. The shell is slender cylindrical and convolute with tapering anterior portion. The last whorl completely covers all previous ones. No ornament is visible on the whorl face except of few spiral furrows on the abapical end of the shell in some specimens (not preserved in most specimens). The aperture stretches over the entire shell height. It is narrow and only somewhat widened anteriorly. It has a columellar callus with one or possibly two plaits.

Remarks.

Volvocylindrites marcousana ranges from the (upper) Oxfordian to the upper Kimmeridgian according to the literature. Spiral furrows are not mentioned in published descriptions. According to the literature this species has one or two plaits on the columella. Cylindrites extensus Maire, 1927 from the upper Rauracien (= middle Oxfordian) is similar but very slender. Similar slender forms have been illustrated by Loriol in Loriol and Bourgeat (1886-1888: pl. 3, figs 6-7) as Volvula marcousana from the upper Kimmeridgian of Valfin. These slender forms are interpreted herein as variations of V. marcousana .

Figures

Plate 21. (1 - 2) Ptychocylindrites condati (Guirand & Ogerien, 1865), Nattheim (collection Sauerborn); (1) apical view, width 5 mm; (2) lateral view, height 12 mm. (3 - 5) Volvocylindrites marcousana (Guirand & Ogerien, 1865). (3) SNSB-BSPG 2021 XV 99, Saal (collection Lang), lateral view, height 5.5 mm. (4 - 5) SNSB-BSPG 2021 XV 100, Saal (collection Lang); (4) lateral view, height 8.8 mm; (5) aperture, height 3.2 mm. (6 - 7) Sulcoactaeon sp. 1, SNSB-BSPG 2021 XV 101, Saal (collection Lang), lateral views, height 3.7 mm.