Danian microfloral provinces in Argentina

Resumen

Two major palaeophytogeoprovinces could be recognized during the Danian in Argentina, based on the palynological record both at the genus or species level and at the palaeocommunity level. In the north Verrustephanoporites simplex Leidelmeyer 1966 (Ulmaceae) is associated mostly with tropical and subtropical families. Nothofagidites pollen in the south is mostly associated with temperate families. In central and northwest Argentina a subprovince with "triprojectate" pollen (Michedlishvilia) could be distinguished. Warm and humid climatic conditions are indicated for the Ulmaceae Phytogeoprovince and more temperate conditions for the Nothofagidites Phytogeoprovince. A brief consideration of the Mesozoic-Cenozoic palaeogeographic and geodynamic evolution of southern South America is also given.