Terrestrial and lacustrine gastropods from the Priabonian (upper Eocene) of the Sultanate of Oman.

Terrestrial and aquatic gastropods from the upper Eocene (Priabonian) Zalumah Formation in the Salalah region of the Sultanate of Oman are described. The assemblages reflect the composition of the continental mollusc fauna of the Palaeogene of Arabia, which, at that time, formed parts of the southeastern Tethys coast. Several similarities with European faunas are observed at the family level, but are rarer at the genus level. These similarities point to an Eocene (Priabonian) rather than to a Rupelian age, although the latter correlation cannot be entirely excluded. At the species level, the Omani assemblages lack any relations to coeval faunas. This suggests the possible presence of a distinct biogeographic province during the Palaeogene or may simply reflect the extremely sparse non-marine fossil record of the Eocene in the Tethys region. The occurrence of the genera and along with some pomatiids, probably related to extant genera, suggests that the modern African-Arabian continental faunas can be partly traced back to Eocene times and reflect very old autochthonous developments. In contrast, the diverse Vidaliellidae went extinct, and the morphologically comparable Neogene Achatinidae may have occupied the equivalent niches in extant environments. Harzhauser and Neubauer nov. gen., Kadolsky, Harzhauser and Neubauer nov. gen., Harzhauser, Kadolsky and Neubauer nov. gen., Kadolsky, Harzhauser and Neubauer nov. gen., Harzhauser and Neubauer nov. gen., Harzhauser and Neubauer nov. gen., Harzhauser and Neubauer nov. gen., Harzhauser and Neubauer nov. gen., Harzhauser and Neubauer nov. gen., H. Nordsieck nov. gen. and H. Nordsieck nov. gen. are introduced as new genera. Harzhauser and Neubauer nov. sp., Kadolsky, Harzhauser and Neubauer nov. sp., Harzhauser, Kadolsky and Neubauer nov. sp., Kadolsky, Harzhauser and Neubauer nov. sp., Harzhauser and Neubauer nov. sp., Harzhauser and Neubauer nov. sp., Harzhauser and Neubauer nov. sp., Harzhauser and Neubauer nov. sp., Harzhauser and Neubauer nov. sp., Harzhauser and Neubauer nov. sp., Harzhauser and Neubauer nov. sp., Harzhauser and Neubauer nov. sp., H. Nordsieck nov. sp., H. Nordsieck nov. sp., and H. Nordsieck nov. sp. are described as new species.