Article: Devonian megaspores from the Wyboston Borehole, Bedfordshire, England

Nine species of megaspores are described from the Geological Survey Wyboston Borehole, Bedfordshire, England. Of these, five species are new, one forming the basis of a new genus, Heliosporites. Two single occurrences of large megaspores referable to Carboniferous genera are recorded, together with a new occurrence of the species Cystosporites devonicus Chaloner and Pettitt. The mean maximum size of all the species represented is 810 p. While this is a higher figure than that for most Devonian megaspores described hitherto, it is still smaller than the corresponding figure for Carboniferous megaspores. The diversity of megaspores now known from the Devonian suggests that heterosporous plants were more abundant at that time than their representation in the macrofossil record would indicate. Some aspects of the classification of the Palaeozic dispersed spores are discussed. The assemblage is regarded as probably of Frasnian age.