Spermatophyte plants that have unenclosed, "naked seeds": The fifth extant division is the flowering plants, also known as angiosperms or magnoliophytes, the largest and most diverse group of spermatophytes. Angiosperms possess seeds enclosed in a fruit, unlike gymnosperms. In addition to the taxa listed above, the fossil record contains evidence of many extinct taxa of seed plants. The so-called "seed ferns" (Pteridospermae) were one of the earliest successful groups of land plants, and forests dominated by seed ferns were prevalent in the late Paleozoic. "Glossopteris" was the most prominent tree genus in the ancient southern supercontinent of Gondwana during the Permian
Evolutionary history of plants and radially symmetrical, is an integumented megasporangium surrounded by a cupule. The megasporangium bears an unopened distal extension protruding above the multilobed integument. It is suspected that the extension was involved in anemophilous pollination. "Runcaria" sheds new light on the sequence of character acquisition leading to the seed. "Runcaria" has all of the qualities of seed plants except for a solid seed coat and a system to guide the pollen to the ovule. The first spermatophytes (literally: "seed plants") – that is, the first plants to bear true seeds – are called pteridosperms: literally, "seed ferns", so called because their