Colubrellopsis, Bandel, 2007

Szabó, János & Jaitly, Anand Kumar, 2019, Additional Middle Jurassic gastropods from Kachchh (western India) in the collections of the Banaras Hindu University (Varanasi, India), Fragmenta Palaeontologica Hungarica 36, pp. 3-30 : 11-13

Colubrellopsis ? sp.

( Figs 29–30 )

Material – Single, damaged specimen; peristome is not cleanable.

Measurement – Inv. No.: BHU 2020I 6; D = 4.1 mm.

Description – The only specimen is the last whorl of a small neritiform shell; the earliest whorls seem fully lacking but a small, uncertain shell remnant on the inner mould suggests non-dissolved inner parts of the penultimate whorl. The peristome and aperture are subaxially elongated and shows lunuliform outline. Outer lip is thickened externally; inner lip is not accessible. The thickenings of the outer lip have been periodically repeated so the available last whorl is rather densely ribbed between the suture and the axial region of the base. The ribs, and consequently the outer lip, are fairly prosocline, slightly prosocyrt; the apertural plane is nearly tangential to the last whorl.

Remarks – The inferred shell remnant seems to be the basal region of the penultimate whorl; its presence suggests belonging of this species to Neritopsidae . The genus of most similar outer morphology is Colubrellopsis ( Colubrellopsinae ) but the characters of the ribs are different; that is why the question mark is necessary after the genus name.

If that shell remnant were a random shell piece in realistic position, the species would be a neritoidean one. Actually, other specimens are necessary to a right identification.

Occurrence – Sadhara, Patcham Island, Eomiodon Redstone Member, Bajocian.

Figures

Figs 17–30. Species of Vetigastropoda, and Neritimorpha.– Figs 17–23. Planiturbo lerensis n. sp., holotype. – 17–20. Apertural, apical, basal, and abapertural views, ×2.8. – 21. Details of the early shell, ×9. – 22. Details of the basal ornament, ×7.6. – 23. Details of the last whorl ornament, ×7. – Figs 24–28. Planiturbo lerensis n. sp., paratype. – 24–27. Abapertural, apertural, basal, and apical views, ×2.8. – 28. Details of the earliest whorls, ×10.3. – Figs 29–30. Colubrellopsis? sp., abaper- tural, and apical views, ×7.3