Diatrypesis, Tomlin, 1929

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 : 16

Diatrypesis ? sp.

( Figs 41–42 )

Material – Single, slightly flatten teleoconch fragment with eroded shell remnants.

Measurements – Inv.No.: BHU 2020I12; H dam.= 23.6 mm, pleural angle:~14°.

Description – Plan of the shell is similar to those of Diatrypesis sp. 1 and sp. 2 above, however, the subsutural carina is represented here by a low, ribbon like elevation without nodules. Sparse, rather strong, straight, sharp ribs cross the whorls on the earliest preserved whorl from suture to suture; on this shell part, their orientation is slightly opisthocline. On the following whorls, the ribs become orthocline and less marked.

Remarks – The differences in the morphology from the above Diatrypesis species may hold generic level taxonomic meaning; however, the state of preservation does not allow to clarify it.

Occurrence – Jumara Dome, Jhurio Formation, Bathonian.

Figures

Figs 31–59. Caenogastropods 1. – Figs 31–33. Zygopleura sp. – 31. Both specimens, ×5.5. – 32. Details of the earliest preserved whorls, ×13.5.– 33. The last whorl specimen from upper left corner of Fig. 31, ×7. – Figs 34–35. Procerithium (Rhabdocolpus)? aff. lorierei (Hebert et Deslongchamps, 1860). – 34. Full view, ×3.3. – 35. Magnified details, ×7. – Fig. 36. Magnified “best” view of Diatrypesis sp. 1, ×3.8. – Figs 37–40. Diatrypesis sp. 2. – 37–38. BHU2020I 10 specimen. – 37. Side view of full remnant, ×3.7. – 38. Details of pattern on the same specimen, ×7. – 39–40. BHU2020I 11 specimen. – 39. Side view of full remnant, ×4.2. – 40. Riblets on the earliest whorl of the same specimen, ×7.2.– Figs 41–42.Diatrypesis? sp.– 41.“Apertural” view of the available, flattened specimen,×1.7. – 42. Side view,×1.7. – Figs 43–59. Exelissa indiana n. sp.– 43–45. Holotype.– 43–44. Apertural, and abapertural view, ×4. – 45. Ornament details of the holotype in ×7.8 magnification. The holotype in Figs 43–44 and six paratypes (BHU2020I 14–19) in Figs 46–59 are equally magnified (×4) to demonstrate the high size variability among the full-grown shells. The same shells well show also the high shape, and ornament variability. The photo in Fig. 58 (BHU2020I 19) is taken parallel to the most frequent final peristome plane, ×6. – Fig. 59. Perpendicular view to the plane of the trumpet like peristome, ×6.2. Detailed data between the figures, the measurements, and the inventory numbers of the types are supplied above, in the species description