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New materials from the Upper Devonian(Famennian) Wutong Formation of Chizhou District,Anhui Province,South China,allow description of fertile and sterile characters of Archaeopteris halliana.This plant has penultimate axes attached by sterile leaves and paired ultimate branches in the same ontogenetic spiral.Sterile leaves are narrowly cuneate in shape and bear distal margins dissected deeply.These leaves are spirally arranged on sterile ultimate axes.Non-laminated sporophylls occur spirally on the ultimate axes and bifurcate once or twice.Elongate sporangia with longitudinal dehiscence are borne adaxially below or above the dividing points of the sporophylls. Despite the leaf shape resembling that of Archaeopteris macilenta,our plant is assigned to A.halliana because of its non-laminated sporophylls.Fertile characters should be given priority or enough consideration in identifying species of Archaeopteris.
New materials from the Upper Devonian (Famennian) Wutong Formation of Chizhou District, Anhui Province, South China, allow description of fertile and sterile characters of Archaeopteris halliana. This plant has penultimate axes attached by sterile leaves and paired ultimate branches in the same ontogenetic spiral . Sterile leaves are narrowly cuneate in shape and bear distal margins dissected deeply. The leaves are spirally arranged on sterile ultimate axes. Non-laminated sporophylls occur spirally on the ultimate axes and bifurcate once or twice. Elongate sporangia with longitudinal dehiscence are borne adaxially or above the dividing points of the sporophylls. Despite the leaf shape resembling that of Archaeopteris macilenta, our plant is assigned to A. isiana because of its non-laminated sporophylls. Certificate characters should be given priority or enough consideration in identifying species of Archaeopteris.