Late Jurassic (Upper Kimmeridgian) Heterobranchia (Gastropoda) of the coral-facies of Saal near Kelheim and the viciniy of Nattheim (Germany)
Author
Gruendel, Joachim
Institut fuer Geowissenschaften, Fachrichtung Palaeontologie, Freie Universitaet Berlin, Malteserstrasse 74 - 100, 12249 Berlin, Germany
joachim.gruendel@lingua-pura.de
Author
Keupp, Helmut
Institut fuer Geowissenschaften, Fachrichtung Palaeontologie, Freie Universitaet Berlin, Malteserstrasse 74 - 100, 12249 Berlin, Germany
Author
Lang, Fritz
Drosselweg 16, 96114 Hirschaid, Germany
Author
Nuetzel, Alexander
https://orcid.org/0000-0002-8852-7688
SNSB-Bayerische Staatssammlung fuer Palaeontologie und Geologie, Richard-Wagner-Str. 10, 80333 Muenchen, Germany & Department of Earth and Environmental Sciences, Paleontology and Geobiology, Ludwig-Maximilians-Universitaet Muenchen, Richard-Wagner-Str. 10, 80333 Muenchen, Germany
text
Zitteliana
2022
2022-12-12
96
179
221
http://dx.doi.org/10.3897/zitteliana.96.e84187
journal article
http://dx.doi.org/10.3897/zitteliana.96.e84187
2747-8106-96-179
35B619086E6548B09A177281C2253391
FE0861D71BB454999EE6637C0D9B2B0C
Ptygmatis? tornata (Quenstedt, 1852)
Morphotype 2 Plate 10: figs 11, 12
2017 - Nerineoidea
Nr. 2 -
Gruendel
: 33, pl. 13D.
Note.
In some specimens, the ramp is not bordered by a sharp crest, but by a more or less pronounced band that is demarcated from the concave part of the whorl face by another edge; there seem to be transitions between both varieties.
Remarks.
Two poorly preserved fragments of
Nerinea cochlearis
Quenstedt, 1881-1884 are present in the Quenstedt collection (
Tuebingen
), both probably representing juveniles. Shape and ornament match the description of
Ptygmatis tornata
given above, as does the number and position of the plaits. Their base is umbilicated. However, these two specimens are too poorly preserved for a safe identification as
Ptygmatis tornata
.
Plate 10.
Ptygmatis? tornata
(Quenstedt, 1852).
(1-10)
Ptygmatis? tornata
(Quenstedt, 1852) morphotype 1.
(1)
SNSB-BSPG 2021 XV 32; Saal (collection Lang); lateral view, height 14 mm.
(2)
SNSB-BSPG 2021 XV 33, Saal (collection Lang), lateral view, height 65 mm (original to
Gruendel
2017
, fig. 13 E).
(3-4)
SNSB-BSPG 2021 XV 34, Saal (collection Lang);
(3)
lateral view, height 20 mm;
(4)
base, width 7 mm).
(5)
SNSB-BSPG 2021 XV 35, Saal (collection Lang), lateral view, height 19 mm.
(6-7)
SNSB-BSPG 2021 XV 36, Saal (collection Lang);
(6)
lateral view, height ca. 50 mm;
(7)
aperture, width 15 mm.
(8-9)
Lectotype; University
Tuebingen
(collection Quenstedt), Nattheim, shell in lateral views, height ca. 30 mm (original
Quenstedt 1881-1884
, pl. 205, fig. 67).
(10)
University
Tuebingen
(collection Quenstedt), Nattheim, lateral view, height ca. 45 mm (original
Quenstedt 1881-1884
, pl. 206, fig. 68).
(11-12)
Ptygmatis? tornata
(Quenstedt, 1852) morphotype 2;
(11)
SNSB-BSPG 2021 XV 37, Saal (collection Lang), lateral view, height 29 mm.
(12)
morphotype 2, SNSB-BSPG 2021 XV 38, Saal (collection Lang), lateral view, height 42 mm (original to
Gruendel
2017
, fig. 13 D).
It remains unclear whether
N. terebra
Schuebler
in Zieten and
N. incavata
Bronn are conspecific with
N. tornata
Quenstedt. At least for
N. terebra
this is likely, because this species was described from Nattheim as is also the case for
Nerinea cochlearis
. Both,
N. terebra
and
N. incavata
, would have priority over
N. tornata
Quenstedt.
Relationships.
Numerous similar species have been described which are hardly distinguishable based on study of the literature alone. In the following, differences to middle Oxfordian and to early Tithonian taxa are discussed.
Nerinea mandelslohi
Bronn sensu Zeuschner (1850) has higher whorls that are more rapidly increasing in width.
Nerinea suevica
Quenstedt sensu
Schlosser (1882)
has higher whorls, and only 3 apertural plaits are known for this species.
Aptyxis paradoxa
Schlosser, 1882 lacks plaits and also shows other differences.
Bactroptyxis cassiope
d'Orbigny
sensu
Fischer and Weber (1997)
has higher whorls, its whorl face is less concave and it has less pronounced bulges; its sutures are situated on the bulge.
Nerinea partschi
Peters, 1855 closely resembles
Ptygmatis? tornata
but has higher whorls and lacks an open umbilicus.
Nerinea gosae
Roemer sensu Goldfuss (1844) resembles the present material in shell shape but its sutures are situated on the bulge. The latter is also the case in
Nerinea acteon
d'Orbigny
sensu
Cossmann (1898)
,
Nerinea baillei
Maire, 1913, and
N. castor
d'Orbigny
sensu
Maire (1927)
.
Nerinea bruntrutana
Thurmann sensu Goldfuss (1844) resembles
Ptygmatis tornata
morphotype 2 in having a band-like, broadened bulge; however, its whorls increase more rapidly in width so that its shape is more broadly conical and it has two palatal plaits.