Aspects of Permian palaeobotany and palynology .15. On the oldest known peltasperms with radically symmetrical ovuliferous discs from the Kungurian (uppermost Lower Permian) of the Fore-Urals (Russia)

Peltaspermum retensorium (Zalessky) Naugolnykh et Kerp, comb. nov., a new representative of the Peltaspermales, is described from the Kungurian of the Fore-Urals. Peltaspermum retensorium has radially symmetrical ovuliferous discs. The pollen organs are similar to those of other peltasperms. With regard to the frond architecture and the cuticle, the foliage of this plant appears to be very similar to that of Autunia Krasser emend. Kerp, a genus of peltasperms with bilaterally symmetrical megasporophylls, known from the uppermost Carboniferous and Lower Permian. Peltaspermum retensorium is the oldest true peltasperm with radially symmetrical ovuliferous organs known from Angaraland.