1. An extinct group of seed-bearing plants from the Paleozoic and Mesozoic eras that combined characteristics of ferns and seed plants.
Usage: paleobotany; plural form; singular is pteridosperm; also called seed ferns

Examples

• Pteridosperms were among the first plants to produce seeds while retaining fern-like leaves.
• Fossils of pteridosperms provide important evidence of plant evolution during the Carboniferous period.
• Scientists study pteridosperms to understand the transition from seedless to seed-bearing plants.
• The discovery of pteridosperm fossils helped paleobotanists reconstruct ancient forests.
• Pteridosperms dominated many Mesozoic ecosystems before flowering plants became prevalent.