Mohrensternia angulata ( Eichwald, 1853 )

Kowalke, Thorsten & Harzhauser, Mathias, 2004, Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys, Acta Palaeontologica Polonica 49 (1), pp. 111-134 : 125

publication ID

https://doi.org/ 10.5281/zenodo.13272499

persistent identifier

https://treatment.plazi.org/id/0386436B-FFE5-FFA3-FCCA-FCB7C19FFDAE

treatment provided by

Felipe

scientific name

Mohrensternia angulata ( Eichwald, 1853 )
status

 

Mohrensternia angulata ( Eichwald, 1853) View in CoL

Fig. 9A, B View Fig .

Rissoa angulata View in CoL sp. nov.; Eichwald 1853: 268–269, pl. 10: 10.

Rissoaangulata Eichwald; Hörnes 1856: 577–578 (partim), pl. 48: 23 a.

Mohrensterniaangulata (Eichwald); Friedberg 1923: 392, pl. 23: 15, 16.

Mohrensternia angulata (Eichwald) View in CoL ; Jekelius 1944: 71, pl. 15: 7, 8.

Mohrensternia angulata (Eichwald) View in CoL ; Papp 1954: 35–36, pl. 5: 27.

Rissoa (Mohrensternia) angulata angulata Eichwald View in CoL ; Boda 1959: 707, pl. 24: 12–16.

Mohrensternia angulata (Eichwald) View in CoL ; Svagrovský 1971: 294–296, pl. 46: 1–9.

Material.— Thirteen specimens from the Early Sarmatian of

Lednicé (formerly Eisgrub) E of Mikulov, Czech Republic,

NHMW 2002z0029/0001.

Description.—The slender shell comprises up to 7 rounded whorls measuring up to 6 mm in height and up to 2.5 mm in width. Whorls slowly increase, separated by incised sutures. Sculpture consists of 10 broad orthocline to slightly opisthocyrt axial ribs whose intensity may decrease in the course of the last whorl. Slender morphs with regularly curving ribs exist alongside those with ribs increasing in thickness in the mid to abapical portion of the whorls. The last whorl forms 50–60% of total shell height. The holostomatous aperture is broad oval to rounded and is characterised by a very thin peristome.

The protoconch has 2.25–2.3 rounded whorls, which appear to be smooth. It measures 0.35–0.36 mm both in maximum diameter and in height. The first whorl measures 0.14–0.15 mm in maximum diameter and 0.03–0.04 mm in the width of the initial cap−like onset. The transition to the teleoconch is indistinct. The onset of the teleoconch is indicated by the formation of wavy axial folds which grade into axial ribs.

Remarks.—The dimension of the protoconch indicates an indirect development with inclusion of a free veliger stage. The veliger spent a brief period of probably one or two weeks within the plankton, feeding on phytoplankton.

Mohrensternia angulata View in CoL is a typical and widespread species during the Early Sarmatian of the Vienna Basin and the Styrian Basin and is also known from Sarmatian deposits of the Mid Danube Basin ( Jekelius 1944), the Carpathian Foredeep ( Friedberg 1923), Slovakia ( Svagrovský 1971), and South−East Europe, e.g., Bulgaria and Romania ( Kolesnikov 1935; Iljina 1998). Svagrovský (1971) noted a certain variability of the shell, with more or less slender outline and variable strength of the axial ribs; this was confirmed by the investigation of our material. Its roots reach back to the Badenian, when it is a rare element throughout the Central Paratethys, documented from Hungary, Poland, and Romania ( Csepreghy−Meznerics 1950; Kokay 1966; Friedberg 1923).

NHMW

Naturhistorisches Museum, Wien

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Order

Littorinimorpha

Family

Rissoidae

Genus

Mohrensternia

Loc

Mohrensternia angulata ( Eichwald, 1853 )

Kowalke, Thorsten & Harzhauser, Mathias 2004
2004
Loc

Mohrensternia angulata (Eichwald)

Svagrovsky, J. 1971: 294
1971
Loc

Rissoa (Mohrensternia) angulata angulata

Boda, J. 1959: 707
1959
Loc

Mohrensternia angulata (Eichwald)

Papp, A. 1954: 35
1954
Loc

Mohrensternia angulata (Eichwald)

Jekelius, E. 1944: 71
1944
Loc

Rissoa angulata

Eichwald, E. 1853: 268
1853
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