Ptygmatis? tornata (Quenstedt, 1852)

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

publication ID

https://dx.doi.org/10.3897/zitteliana.96.e84187

publication LSID

lsid:zoobank.org:pub:35B61908-6E65-48B0-9A17-7281C2253391

persistent identifier

https://treatment.plazi.org/id/08522836-166A-591F-BE72-EE3ED775C8E3

treatment provided by

Zitteliana by Pensoft

scientific name

Ptygmatis? tornata (Quenstedt, 1852)
status

 

Ptygmatis? tornata (Quenstedt, 1852)

Morphotype 2 Plate 10: figs 11, 12 View Plate 10

2017 - Nerineoidea Nr. 2 - Gründel: 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 ( Tübingen), 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 .

It remains unclear whether N. terebra Schübler 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.

Kingdom

Animalia

Phylum

Mollusca

Class

Gastropoda

Family

Ptygmatididae

Genus

Ptygmatis

Loc

Ptygmatis? tornata (Quenstedt, 1852)

Gruendel, Joachim, Keupp, Helmut, Lang, Fritz & Nuetzel, Alexander 2022
2022
Loc

2017 - Nerineoidea

Sharpe 1850
1850