The First Seed Plants

The first seed plants were seed ferns and some primitive conifers. All of these can be called gymnosperms, forms where in the seeds are not enclosed within ovaries. Seed ferns that bore seeds on their leaves appeared during the Carboniferous period of the Paleozoic era, approximately 340 to 280 million years ago. Although these ferns became extinct during the Mesozoic era, the plants that evolved into modem seed plants probably trace their origin to them.