I collect this from the Maastrichtian of South India. A short description is given below.
Shell dextrally coiled, conical. Protoconch not discernible. Basal part of all specimens are broken, only the apical part of the species found to be preserved. Moderately inclined broad ramp present which is separated by an angulation (shoulder) from the nearly vertical outer whorlface. Suture impressed. Preserved shell shows very high whorl expansion rate. Shell surface smooth.
This can belong to several quite different gastropods- depending on shell structure- in case it is calcite perhaps a member of the Neritimorpha, in case the shell is not preserved it could also represent the apex of a gastropod species with lecithotrophic development and it could also be related to Thylacus- a member of the limpet-like caenogastropods around Hipponix and Crepidula which had limpet like species in their Cretaceous relation.
Than you Dr. Bandel.
Can you suggest some papers (realted to taxonomy) ragarding those gastropods you mentioned.
Bandel, K. (2003): Cretaceous volutid Neogastropoda from the Western Desert of Egypt and their place within the Neogastropoda (Mollusca). - Mitt. Geol.-Paläont. Inst. Univ. Hamburg, Heft 87, p 73-98, 49 figs., Hamburg.
has similar protoconch,
Bandel, K. & Riedel, F. (1994): Classification of recent and fossil Calyptraeoidea with a discussion on neomesogastropod phylogeny. - Berliner geowissenschaftliche Abhandlungen, E 13: 329-367, Berlin
for Caenogastropod limpets
Bandel, K. (1992): Platyceratidae from the Triassic St. Cassian Formation and the evolutionary history of the Neritomorpha (Gastropoda). - Paläontologische Zeitschrift, 66:231-240
about similar Neritomorpha
Mustafa, H. & Bandel, K. (1992): Gastropods from lagoonal limestones in the Upper Cretaceous of Jordan. - Neues Jahrbuch Geologie und Paläontologie, Abhandlungen 185:349-376, Stuttgart. Neritomorpha
Your specimen does not show the first whorl- and that is important for recognizing the mode of development- with a lot of yolk or with little yolk- thus simplified early ontogenetic shell of limpet like teleoconch.
Klaus has given you some important insights into its potential taxonomic position. Before you succumb - as we all do too easily - to trying to match pictures it is essential that you obtain as much morphological information from the fossil as you can. Here are some practical comments that might be useful.
Original shell mineralogy may or may not be preserved. Look at broken shell cross-sections and also compare with those co-occurring gastropods in which you can easily infer their original shell structure. It is often very useful to consider the preservation of your studied gastropod in relation to that of the whole mollusc fauna.
The most important gross feature that you need to determine is whether the shape of the base is flat or whether it would have been elongated - try to prepare the base on the most likely specimens.
Another extremely important feature is the shape and orientation of the aperture. What is the orientation of the growth lines on the side of the whorl? The morphology and orientation of the aperture (as revealed by growth lines) is often ignored in taxonomic descriptions yet is is vital to a correct understanding of coiling geometry and taxonomic interpretation in gastropods. If these growth lines are strongly prosocline then it may allow you to exclude some of Klaus's suggestions, for example that the shell just represents the top of a much taller gastropod (e.g. Volutidae or similar).
Good luck!
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