Urfarne
The division of living beings into systematics is a continuous subject of research. Different systematic classifications exist side by side and one after the other. The taxon treated here has become obsolete due to new research or is not part of the group systematics presented in the German-language Wikipedia.
As Urfarne (Psilophytopsida; Greek paddos = "naked, bald") are sometimes the original groups of vascular plants summarized.
It is the most primitive group of vascular pore plants, with primordial telomas , completely smooth or with emergences , with proto- or actinostele. Real roots were missing. The sporangia were single and terminal or arranged in ears, with a multilayered wall of the sporangia, they were isospore. They originated around 420 million years ago, in the Ludfordium at the transition from the Silurian to the Devonian , and were already extinct again in the Upper Devonian .
However, since the ancient ferns are not closely related, they were later divided into the three clans Rhyniophyta , Trimerophytophyta and Zosterophyllophyta .
literature
- Eduard Strasburger , Peter Sitte, Elmar Weiler, Andreas Bresinsky, Christian Körner: Textbook of botany for universities . Founded by E. Strasburger. Gustav Fischer, Stuttgart 1998 (34th edition). ISBN 3-4372-5500-2
- Paul Kenrick, Peter R. Crane: The Origin and Early Diversification of Land Plants. A Cladistic Study . Smithsonian Institution Press, Washington and London 1997. ISBN 1-56098-729-4