A review of the Middle-Late Devonian lycopsids

This paper gives a summary of the representative lycopsids of the Middle-Late Devonian, and investigates the variation and differentiation of their reproduction structures, root organs and anatomical characters. Concerning the taxonomic treatment, some of these lycopsids can be attributed to Lycopodiales, Protolepidodendrales and Isoetales sensu lato, while the others cannot be classified into current system. Because of preservation factors and uniqueness of the characters, it is unclear that to what extent these taxa reflect a taxonomical diversity. These lycopsids demonstrate great complexities in reproduction structures, root organs and anatomy. These findings, on one side, broaden current knowledge about the early evolutionary history of the lycopsid characters, and on the other side, indicate that those satellite taxa should also be taken into consideration besides those whole or almost whole species when making a phylogenetic analysis.