New Marine Ostracod Species from the Upper Barremian (Lower Cretaceous) of the Cuenca Ranges (Central Spain): Implications for Marine Incursions in the Western Tethys

The upper Barremian (Lower Cretaceous) palaeontological sites of Vadillos-1, Vadillos-2, and Las Majadas are located in the northern part of the province of Cuenca, Central Spain. These Wealden-type successions are interpreted as predominantly non-marine deposits, although recent studies have revealed new brackish and marine ostracod assemblages, indicating fluctuating salinity conditions. Five marine ostracod species have been identified for the first time in samples from the Vadillos-1 and Vadillos-2 successions, two of them being new species: Asciocythere uralte nov. sp., Metacytheropteron aronnaxi nov. sp., Neocythere (Neocythere) sp. 1, Cytherelloidea sp. 1, and Polycope sp. 1. The presence of these previously unknown taxa provides new and valuable palaeoecological data, revealing occasional marine influence within these deposits and contributing to an improved understanding of ostracod taxonomic diversity and a more refined reconstruction of the palaeoenvironmental evolution of the non-marine to transitional upper Barremian palaeoenvironments of the Western Tethys.