Brachiopods and bryozoans from the Sandberg section (Vienna Basin, Central Paratethys) and their significance for environmental interpretation of the Early Sarmatian (= Middle Miocene) Sea

Abstract

Brachiopods and bryozoans are described for the first time from the upper part of the Sandberg section (Vienna Basin, Central Paratethys, Slovakia) dated by foraminifers and calcareous nannoplankton as Early Sarmatian (= Late Serravallian). Three brachiopod species, i.e. Gryphus miocenicus (Michelotti, 1847), Argyrotheca cuneata (Risso, 1826) and Joania cordata (Risso, 1826), have been identified. Bryozoans are represented by at least 11 species, i.e. Umbonula macrocheila (Reuss, 1847), Margaretta cereoides (Ellis et Solander, 1786), Plagioecia rotula (Reuss, 1847), Schizoporella dunkeri (Reuss, 1847), Calpensia gracilis (Munster, 1826), Escharella tenera (Reuss, 1874), Mollia cf. patellaria (Moll, 1803), Vibracella trapezoidea (Reuss, 1847), Smittina cervicornis (Pallas, 1766), Porella sp., and an unidentified calloporid. Despite the fact that brackish conditions are commonly expected in the Vienna Basin during this period, the assemblage indicates full marine (stenohaline) conditions.