Lower Palaeozoic sporomorphs: their stratigraphical distribution and possible affinities

Abstract

Richardson & Ioannides (1973) speculated on possible bryophytic affinities of some Silurian dispersed spores. Later, at the International Palynological Congress in Cambridge (1980) I discussed the close morphological similarities of some Silurian and early Devonian spores to those from mosses and liverworts. In particular the dispersed miospore genera Streelispora and Aneurospora are similar to the spores of the extant liverwort Anthoceras and spores of some species of the extant moss genus Encalypta to fossil spores of Emphanisporites . If such similarities are indicative of affinity then many of the Silurian spores may have belonged to early bryophytic ancestors. As mosses and liverworts are not usually preserved as fossils, such an explanation would help to explain the major discrepancy between the number of dispersed Silurian and Lower Devonian miospore species and the few species of land plants known.