A seagrass-associated Early Miocene Indo-Pacific gastropod fauna from South West India (Kerala)

摘要

An Early Miocene gastropod fauna of the Kerala Basin in South West India is described. In total, 187 species are documented from the area based on new collections and previous literature records. The collecting campaign focused on small sized shells and thus resulted in a surprising amount of new microgastropods. In this paper, 105 species are discussed, of these, 47 are formally described as new species and 27 are discussed as new species in open nomenclature. Only ~ 30 % of the fauna has been documented in earlier studies. In contrast, only ~ 35 % of the previously known taxa have been found again in the new samples. This relation documents the potential of this highly diverse Burdigalian fauna, which might be a key for the understanding of the diversification in the Indian Ocean and the Indo-West Pacific Region. The composition of this seagrass-associated assemblage suggests an at least Burdigalian origin of this faunal- type. The following taxa are introduced as new species: Pagodatrochus boehmae n. sp., Solariella keralaenis n. sp,,Jujubinus keralaensis n. sp., Clelandella sovisi n. sp., Perrinia krohi n. sp., Bothropomapseudomunda n. sp., Skenea indica n. sp., Scaliola subbella n. sp., Scali- ola vastiiica n. sp., Finella bruchae n. sp., Clathrofenella indica n. sp., Gibborissoia inexpectata n. sp., Obtortio wesselinghi n. sp., Cerithi- dium channakodiense n. sp., Haustator ashtamudensis n. sp., Rissolina landaui n. sp., Zebina zuschini n. sp., Monoplex kritscheri n. sp., Biplex alanbeui n. sp., Circulus keralaensis n. sp., Belonimorphis kronenbergi n. sp., Monophorus invectus n. sp., Teinostoma mandici n. sp., Pyreneola lukenederi n. sp., Fusinus roetzeli n. sp., Dermomurex (Viator) teschlernicolae n. sp., Alocospira uter n. sp., Kermia bulbosa n. sp., Microdaphne indohystrix n. sp., Pleurofusia wanzenboecki n. sp., Mitromorpha bellula n. sp., Discotectonica nuda n. sp., Heliacus (Torinista) goehlichae n. sp., Babella robusta n. sp., Chrysallida malabarica n. sp., Menesthella quilonica n. sp., Bulicingulina pharos n. sp., Turbonilla lacrimabunda n. sp., Eulimella reuteri n. sp., Megastomia quilonica n. sp., Acteon aubrechti n. sp., Ringicula quilonica n. sp., "Philine" pulvinifera n. sp., Retusa ashtamudiensis n. sp., Liloapilleri n. sp., Volvulella staphylemorpha n. sp., and Pyrunculus meta- formis n. sp.