Fossil Record 19(1): 1-9, doi: 10.5194/fr-19-1-2016
Two new species of megasporangiate Sigillariostrobus Schimper (Sigillariostrobaceae) fructifications from the British Coal Measures
expand article infoB. A. Thomas, Leyla J. Seyfullah§
‡ Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Penglais, Aberystwyth, Ceredigion, United Kingdom§ Department of Geobiology, University of Göttingen, Göttingen, Germany
Open Access
The arborescent lycophyte group known as the sigillarians borepedunculate fructifications, including Sigillariostrobus Schimper, which has a knownpropensity to disaggregate, making comparisons of cones and in situ spores oftendifficult if not impossible. Sigillariostrobus is monosporangiate, containing eithermegaspores or microspores. Two new species of Sigillariostrobus with megaspores are describedfrom the British Coal Measures. Two cones of Sigillariostrobus saltwellensis sp. nov. are described fromLangsettian–Duckmantian strata of Great Britain, containing in situLaevigatisporites glabratus (Zerndt) Potonié and Kremp spores, making this the first BritishSigillariostrobus species described containing such spores. Sigillariostrobus barkeri sp. nov. is given here to thepreviously described cone with in situ Tuberculatisporites brevispiculus (Schopf) Potonié and Kremp spores. Thisis the first Sigillariostrobus cone with this megaspore species in situ, and thus shows that T. brevispiculus and T. mamillarius(Bartlett) Potonié and Kremp are not conspecific as others havepreviously suggested.