Dinoflagellates are generally unicellular algae with a complex life cycle, living in most aquatic environments. Depending on the dinoflagellate group, asexual and sexual reproduction can take place to a varying extent.
Asexual reproduction occurs mainly through the fission of a haploid motile dinoflagellate cell.
During sexual reproduction, the motile cell produces gametes, which merge into a planozygote stage. During the last decades, it has become more and more apparent that dinoflagellates are sensitive to environmental change. This sensitivity is expressed in sediments through changes in the species composition of dinocyst assemblages in relation to environmental variability. As such, variations in the cyst assemblage can reflect variation in environmental parameters such as temperature, salinity, nutrient concentrations and water stratification. Therefore, we can use fossil dinocysts as tools for reconstructing palaeoenvironment, palaeoclimate, palaeoecology and palaeoceanography.