Sinopse dos estudos de quistos de dinoflagelados fósseis em Portugal

Dinoflagellates are microorganisms, essentially single-celled, which together with other phytoplankton produce food for larger organisms and occupy most aquatic environments, from freshwater habitats and brackish to marine plankton. They present a great variety of vital strategies, being sensitive to temperature and salinity, oxygenation, luminosity and availability of mineral nutrients in the environment. Certain species of dinoflagellates can produce resting stages, called dinoflagellate cysts or dinocysts, settling on sediments. These cysts are made up of chemically inert material, allowing their fossil record. They are a biostratigraphical tool of great value, in addition to serving as paleobiogeographic and paleoenvironmental indicators. Pais (1978) made the first characterization of fossil dinoflagellates in Portugal and, since then, the number of studies in the national territory has been growing. The first works essentially present photographic documentation and/or brief descriptions, and sometimes they use dinocysts as biostratigraphical markers. Since the beginning of this century, information has been enriched with important researches. Detailed biostratigraphical studies have been carried out, correlations have been established between the biostratigraphy of dinocysts and other fossiliferous groups, correlations have been made with other sedimentary basins in the country and from the planet, litho- and chemostratigraphic profiles were built based on geochemical analyzes, palinofacies were studied and paleoenvironments and paleogeography were analyzed and characterized. In the present work, we propose to present a synthesis of the scientific studies documented and inventoried with these microfossils in national territory and the important knowledge that has been obtained, still getting useful information for the research and exploration of energy resources.