Testate amoebae from the Early Jurassic of the western Tethys, north-east Italy

Fossil testate amoebae and their non-marine finds are rare so their ecological importance through Earth history is poorly understood. The Lower Jurassic shallow water black-shales of Trento Platform (north-east Italy) are rich in micro-organisms and contain a thecamoebian and ostracod assemblage representing the first known record of Early Jurassic oligohaline forms from the European mainland. The thecamoebians are represented by the genera Difflugia, Pontigulasia and Centropyxis. The present discovery of Lower Jurassic thecamoebians in fine carbonate organic-rich deposits indicates, for the first time, that these sediments can preserve testate amoebae very well. The occurrence of difflugid testate amoebians confirm a transitional marine-terrestrial habitat, outside large bodies of water, and suggests occasional eutrophication in ephemeral restricted aquatic environment in the Sinemurian–Pliensbachian of the Trento Platform.