The ultrastructure of Cyclusphaera psilata from the Cretaceous of Argentina

Abstract

The fine structure and morphology of Cyclusphaera pollen collected from the early Cretaceous of Argentina is described. The diporate grains possess an exine structure that combines features of both angiosperms and gymnosperms, and raises questions as to the validity of using certain pollen characters in the identification of major taxonomic groups through time. © 1987, Taylor & Francis Group, LLC. All rights reserved.