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| Pteridospermatophyta Fossil range: Devonian-Eocene |
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Pteridospermatophyta, also called seed ferns, is an extinct spermatophyte group of the Plantae kingdom. Members of this division were predominant at the late Devonian, declined some , and mostly disappeared by the Cretaceous, though fossil evidence indicates that they survived into the Eocene in Tasmania.[1] The Pteridospermatophyta have not yet acquired a clear position in botanical systematics and indeed appear to be a paraphyletic form taxon. Some appear to be allied or ancestral to the gymnosperms, others seem to be closer to angiosperms.
The seeds of seed ferns develop differently from the other seed plants, as they are believed to grow inside a cupule.
Orders often united in the seed ferns are:
- Arberiales
- Calamopityales
- Callistophytales
- Corystospermales
- Gigantopteridales (= "Gigantonomiales")
- Glossopteridales
- Leptostrobales
- Peltaspermales
References
- ^ McLoughlin, S., R.J. Carpenter, G.J. Jordan, & R.S. Hill. (2008). "Seed ferns survived the end-Cretaceous mass extinction in Tasmania." American Journal of Botany, 95: 465-471.
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- This page was last modified on 13 July 2008, at 19:46.
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