Subdivision of the dinoflagellate cyst Family Suessiaceae and discussion of its evolution

Abstract. The recent description of Umbriadinium mediterraneense Bucefalo Palliani & Riding 1997 from the Early Jurassic of central Italy and Greece has provided new information on the phylogeny of the dinoflagellate cyst Family Suessiaceae. On the basis of the morphology of the five suessiacean genera, a subdivision of the family into two new subfamilies is proposed. These are the Late Triassic Suessioideae and the Early Jurassic Umbriadinoideae. The evolution of the Family Suessiaceae is related to the evolution of scleractinian corals, largely on the basis of the similarity of their evolutionary patterns and geographical palaeodistributions.