Fish otoliths from the Konkian (Miocene, early Serravallian) of Mangyshlak (Kazakhstan): testimony to an early endemic evolution in the Eastern Paratethys

摘要

Reconstruction of fossil teleost faunas can provide important information on palaeoenvironments, palaeogeography and evolution, and otoliths are particularly useful for that purpose. Here we present an otolith-based fish fauna from the middle Miocene of the Eastern Paratethys, i.e. the Karagaily section of the Mangyshlak Peninsula in Western Kazakhstan, and report on the accompanying nannoplankton, foraminifera, molluscs and ostracods. A total of 30 teleost species are described and figured, including ten new species: Alosa paulicrenata n.sp., Morone? bannikovi n.sp., Centracanthus pobedinae n.sp., Genyonemus? karagiensis n.sp., Trewasciaena suzini n.sp., Parablennius prokofievi n.sp., Aphia djafarovae n.sp., Neogobius udovichenkoi n.sp., Ponticola zosimovichi n.sp., Pomatoschistus bunyatovi n.sp. Nannoplankton and gastropods indicate a Konkian (late Badenian, early Serravallian) age for this fish assemblage. The dominance of Gadidae and Gobiidae, together with the composition of the nannoplankton, indicates an inner-neritic to coastal environment with high productivity. The Konkian fish fauna of the Eastern Paratethys shows a high degree of autonomy relative to approximately contemporaneous fish faunas from the Central Paratethys and other European basins. This confirms that the Konkian was a time of limited faunal exchange between the Central and Eastern Paratethys, while a marine connection may have persisted between the Central Paratethys and the northern Mediterranean. We conclude that the fish fauna reported here records an early endemic development in the Eastern Paratethys during the middle Miocene (Konkian). The disappearance of Bregmacerotidae and Gonostomatidae (Bonapartia) during the preceding stage of the Karaganian and the first appearance of Palimphemus minusculoides in the Konkian are important biostratigraphical markers.