TY - JOUR A1 - Libertin,M. A1 - Bek,J. T1 - Bolsovian Calamostachys incrassata (Nemejc) emend. and its spores from the Kladno-Rakovnik Basin of the Czech Republic JF - Bulletin of Geosciences JA - Bull. Geosci. Y1 - 2006 VL - 81 IS - 3 SP - 207 EP - 213 CY - Prague PB - Czech Geological Survey SN - 1803-1943 (online), 1802-6222 (print) AV - Free KW - Calamites KW - in situ spores KW - Calamospora KW - Calamostachys KW - Pennsylvanian KW - Czech Republic AB - The present article recommends the emendation of the species Calamostachys incrassata, proposed by Nemejc (1953), which was based on one specimen from the Rako Mine near Lubna in the Kladno-Rakovnik Basin. The stratigraphical position of the specimen is the Lower Bolsovian. The inner morphology of Calamostachys incrassata and its in situ spores are described for the first time. The morphology of Calamostachys incrassata cones differs from that of all other known species of calamitean strobili. Most in situ microspores possess a very thin pseudosaccus-like layer that envelopes the trilete inner body of the Calamospora-type. Microspores with an outer exine layer are morphologically similar to some dispersed miospore species of the genera Auroraspora, Remysporites, Callialasporites, Perotrilites, Phyllothecotriletes and Diaphanospora. ER -