FLORA AND VEGETATION DURING THE JURASSIC AND CRETACEOUS PERIODS

Abstract

The successive floras and vegetation which inhabited the Earth from the big extinction at the end of Permian until the extinction at the Cretaceous/Tertiary (K/T) boundary are discussed. These different floras, and consequently the different vegetational cover are of major interest from several points of view, and particularly the present of primitive angiosperms. The origin of the angiosperms and their later radiation constitutes one of the main challenges in Evolutionary Biology. Additionally, it appears that the greatest floristic changes that took place on planet Earth corresponded to Mesozoic times. These important changes were matched by equally important changes in the faunal associations and particularly by the appearance, radiation and extinction of the dinosaurs, which is the group of animals that has exerted the most powerful attraction on the public. The brief synthesis of the floras corresponding to the Jurassic and Cretaceous periods in the Euramerica region also takes into account the palaeogeographical and palaeoclimatological relationships. The floristic changes are analysed in the context of plant/animal relationships.