Bolsovian Calamostachys incrassata (N??mejc) emend. and its spores from the Kladno-Rakovn?-k Basin of the Czech Republic

摘要

ThepresentarticlerecommendstheemendationofthespeciesCalamostachysincrassata,proposedbyN??mejc(1953),whichwasbasedononespecimenfromtheRakoMinenearLubn??intheKladno-Rakovn?-kBasin.ThestratigraphicalpositionofthespecimenistheLowerBolsovian.TheinnermorphologyofCalamostachysincrassataanditsinsitusporesaredescribedforthefirsttime.ThemorphologyofCalamostachysincrassataconesdiffersfromthatofallotherknownspeciesofcalamiteanstrobili.Mostinsitumicrosporespossessaverythinpseudosaccus-likelayerthatenvelopesthetrileteinnerbodyoftheCalamospora-type.MicrosporeswithanouterexinelayeraremorphologicallysimilartosomedispersedmiosporespeciesofthegeneraAuroraspora,Remysporites,Callialasporites,Perotrilites,PhyllothecotriletesandDiaphanospora.