The first compression fossils of Spencerites (Scott) emend., and its isospores, from the Bolsovian (Pennsylvanian) of the Kladno-Rakovník and Radnice basins, Czech Republic

Nearly 60 compression fossils of the vegetative stems and fertile zones of Spencerites (Scott) emend. are described from the Bolsovian of the Kladno-Rakovník and Radnice basins in the Czech Republic. Spencerites is re-interpreted as a pseudoherbaceous, repeatedly (minimum three times) dichotomously-branching, lycopsid with fertile apical zones. Vegetative stems are described for the first time. Two new species are proposed: Spencerites havlenae and Spencerites chaloneri. They are generally similar morphologically, and can be distinguished mainly by their isospores. Spencerisporites radiatus Felix and Parks, 1959 emend. isospores were isolated from Spencerites havlenae and Spencerisporites striatus sp. nov. from Spencerites chaloneri. Emendations are proposed for the generic diagnoses of Spencerites and Spencerisporites, and the specific diagnosis of Spencerisporites radiatus.