Morphological diversity of the exine sculpture of some Frasnian spores from the northern Timan: Applications for taxonomy and significance for spore dispersal

Microspores and megaspores from micro-and megasporangia of a Late Frasnian plant from the northern Timan are identified as the genus Cristatisporites and Ancyrospora, respectively. The exine sculpture is studied in in situ spores, as well as in dispersed miospores of Cristatisporites, Ancyrospora, and Hystricosporites, found in the rock enclosing the plant. The use of exine appendages as a generic level character is proposed. The shape of appendage extremities and the presence of irregular holes in the exine that are considered to be probable insect feeding damage, allowing us to consider wingless insects as main dispersal agents of the spores.