Definition that contains seed fern
- lyginopteris genus of fossil seed ferns of the Carboniferous
- cycadofilicales fossil gymnospermous trees or climbing plants from the Devonian: seed ferns
- order cycadofilicales fossil gymnospermous trees or climbing plants from the Devonian: seed ferns
- genus lyginopteris genus of fossil seed ferns of the Carboniferous
- order lyginopteridales fossil gymnospermous trees or climbing plants from the Devonian: seed ferns
- lyginopteridales fossil gymnospermous trees or climbing plants from the Devonian: seed ferns
- pteridospermopsida extinct gymnosperms most of Carboniferous to Jurassic: seed ferns and allies
- class pteridospermopsida extinct gymnosperms most of Carboniferous to Jurassic: seed ferns and allies