A limnic ostracod fauna from the surroundings of the Central Paratethys (Late Middle Miocene/Early Late Miocene; Styrian Basin; Austria)

Abstract

Aquatic biota of the marine Middle Miocene Paratethys and the Late Miocene Pannonian Lake, a long-lived lake in Central and Eastern Europe, are well known. However, knowledge of the marginal freshwater environments is still rather poor. Recently, a thin-shelled ostracod fauna was discovered in Late Sarmatian to Early Pannonian sediments of a clay pit at the northern margin of the Styrian Basin (St. Stefan, N Graz). 11 taxa are described taxonomically of which some are left in open nomenclature due to insufficient preservation: Vestalenula cylindrica (Straub, 1952), Paracandona cf. euplectella (Robertson, 1889), Candona ( Camptocypria) gratkornensis n. sp., Candona (?) sp., cf. Candonopsis arida Sieber (1905), ? Cypria sp., Cyclocypris nitida Sieber (1905), cf. Bradleystrandesia reticulata (Zaddach, 1844), Stenocypris sp., ? Cypridopsis sp., “Striate ostracod sp.”. The ostracod associations point to a shallow, sometimes richly vegetated, limnic environment. Indications of a “warm”, maybe subtropical climate are suggested by the occurrences of Vestalenula, cf. Candonopsis, ? Cypridopsis and Stenocypris. The ostracod fauna indicates a freshwater environment, detached from the marine Sarmatian Sea and respectively from the brackish Pannonian Lake and provides hereby an insight into the palaeohabitats of the surrounding wetlands.