Fig. 3 in A new isoetalean microsporophyll from the latest Albian of northeastern Spain: Diversity in the development and dispersal strategies of microspores

Fig. 3. In situ masses of microspores of isoetalean microsporophyll (MPZ 2010/919) from Estercuel locality, latest Albian. A. Detail of the microsporangium with six masses of microspores, some of them showing a false "trilete" mark (arrows) probably due to a post-sedimentary compression process. B, D. Masses of hundreds of microspores, the false "trilete" mark due to compaction within adjacent polygonal bodies inside microsporophyll (arrow). C. Detail of microspores presumably grouped in tetrads (arrows) showing both proximal and distal faces. B–D, SEM micrographs. Scale bars: A, 5 mm; B, D, 100 μm; C, 20 μm.