Review of some Hystricosporites representatives from Bolivia

A taxonomic study of megaspores with bifurcate-tipped processes from the Devonian–Carboniferous transition of Bolivia was performed. Megaspore specimens were isolated from palynological samples of the Pando X1 and Manuripi X1 boreholes. Their morphological characteristics and wall structures were described and illustrated with transmitted optical light, ultraviolet fluorescence, and scanning electron microscopy. This megaspore assemblage comprised six fossil species of Hystricosporites (H. costatus, H. delectabilis, H. elongatus, H. expandus, H. furcatus and H. spiralis). The morphologic features of their sporoderms confirm that these megaspores with bifurcate-tipped processes could have had a botanical affinity related to lycopsids. Additional future studies of wall ultrastructure using transmission electron microscopy will provide more information about their phylogenetic relationships with fossil and extant lycopsids.