progymnosperm การใช้

Noeggerathiales have been previously linked to horsetails and ferns, but are currently believed to be progymnosperms.
These were joined by progymnosperms, which rooted up to about a metre deep, during the ensuing Frasnian stage.
Rothwell's analysis separates the " trimerophytes " and progymnosperms, with only the latter being closely related to seed plants.
In Late Devonian times, another group of progymnosperms gave rise to the first really large trees known as " Archaeopteris ".
They probably evolved from a group of Late Devonian progymnosperms known as the Aneurophytales, which had large, compound frond-like leaves.