Article: A seed megaspore from the Devonian of Canada
A megaspore tetrad, Cystosporites devonicus sp. nov., is described from the Upper Devonian of Scaumenac Bay, Quebec, Canada. Cystosporites megaspores have previously been reported only from the Carboniferous, where they have been found in the lycopod seed Lepidocarpon. The occurrence of this Canadian Cystosporites shows that a level of heterospory equivalent to that reached by Lepidocarpon had already been attained by the late Devonian.