ABSTRACT: Three new species of ostracodes are reported from the dinosaur-bearing Escucha Formation at Ariño in Eastern Spain (Iberian Range): Rosacythere denticulata sp. nov., Theriosynoecum escuchaensis sp. nov. and Theriosynoecum arinnoensis sp. nov. Associated charophyta include Clavator harrisii harrisii and Clavator harrisii zavialensis indicating a Lower Albian age, therefore extending the stratigraphic range of the genus Theriosynoecum into the Albian in southern Europe. The environment of deposition for the dinosaur bonebed is interpreted as permanent lacustrine given the association of limnic ostracodes and charophytes.