Progymnospermopsida (progymnosperms) The ancestors of the gymnosperms, which arose in the Devonian and dwindled to extinction in the latter part of the Carboniferous. They had trunks with wood resembling that of gymnosperms, but their fertile branches or leaves bore sporangia (see SPORE), and their foliage was often fern like. Probably seeds evolved in various different progymnosperms. See ARCHAEOPTERIS.

Progymnospermopsida The ancestors of the gymnosperms, which arose in the Devonian and dwindled to extinction in the latter part of the Carboniferous. Probably seeds evolved in various different progymnosperms.