The use of the microalga Botryococcus in the interpretation of lacustrine environments at the Jurassic–Cretaceous transition in Sweden

Ultrastructural studies of developmental stages, shapes and size of fossil microalgal Botryococcus colonies, found in the Vitabäck clays at Eriksdal in southern Sweden, have been carried out. The results of this study, by analogy with the modern alga, suggest that for these lacustrine environments short limited periods of stable, uniform climatic conditions were interspersed with longer periods of seasonal climatic changes during the deposition of the Jurassic–Cretaceous transition sediments in Sweden.