Late miocene molluscs of the Morskaya 2 site (Azov sea region, Russia)

Abstract

Clays and sands of the Morskaya 2 site in the northeastern Azov Sea region con-tain an assemblage of freshwater and marine molluscs. The site known since the early twentieth century as “Paludina beds” has been alternatively attributed to either Late Pliocene or Late Miocene. Our study shows that the site yielded two assemblages with one composed of Middle Sarmatian (Bessarabian) marine species (M1) and the other containing freshwater and terrestrial molluscs of late Maeotian age (about 7-6 Ma) (M2) with redeposited Bessarabian marine forms. The former assemblage was dated by the vertebrate fauna to the late Turolian and MN13 unit of the West European mam-malian biostratigraphical scheme. This level correlates to the Messinian of the International Chronostratigraphic Chart. Ecological preferences in humidity, vegetation, etc. of the terrestrial and freshwater molluscs indicate the presence of a freshwater body rich in aquatic vegetation with a periodical current and a probable connection with a brack-ish water body located near the Palaeo-Don river delta. Deciduous forests, bushes, and meadows grew on the banks of this basin. The presented revision of molluscs from Morskaya 2 elucidates the composition and correlations of the late Miocene non-marine fauna in the southeast Europe and includes a description of molluscan assem-blages, a discussion of systematic position of the studied molluscs, and a palaeoenvi-ronmental reconstruction of the freshwater basin and its surroundings.