Archaeopteris from the Upper Famennian of Belgium: heterospory, nomenclature, and palaeobiogeography.
New fertile specimens of Archaeopteris roemeriana from Upper (but not uppermost) Famennian strata of Belgium have been studied. Crowded sporangia are borne on non-laminate, three times bifurcate fertile leaves helically arranged around the fertile ultimate axes. Vegetative leaves occur both proximal and distal to the fertile leaves. Heterospory is demonstrated with miospores belonging to the Geminospora-Aneurospora complex and macrospores most probably to Contagisporites genus. The established morphological traits allow us to substantiate a synonymy between A. roemeriana and A. halliana. The apparent dominance of A. halliana on the eastern side of the Acadian mountains during Late Famennian times is discussed.
Fairon-Demaret
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Department of Palaeobotany, Services associés de Paléontologie, University of Liège, Allée du 6 Août, Sart Tilman-Bât. B18, B-4000 1, Liège, Belgium
Leponce
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Streel
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