| Medullosales Temporal range:
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|---|---|
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| Neuropteris ovata Hoffmann, Late Carboniferous of northeastern Ohio. | |
Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Division: | †Pteridospermatophyta |
| Order: | †Medullosales Corsin, 1960 |
| Families | |
| Synonyms | |
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The Medullosales is an extinct order of pteridospermous seed plants characterised by large ovules with circular cross-section and a vascularised nucellus, complex pollen-organs, stems and rachides with a dissected stele, and frond-like leaves.[1] Their nearest still-living relatives are the cycads.[2]
Most medullosales were small to medium-sized trees. The largest specimens were probably of genus Alethopteris, whose fronds could be 7 metres long[3] and the trees were perhaps up to 10 metres tall. Especially in Moscovian times, many medullosales were rather smaller, with fronds only about 2 metres long, and apparently growing in dense, mutually supporting stands.[4] During Kasimovian and Gzhelian times there were also non-arboreal forms with smaller fronds (e.g. Odontopteris) that were probably scrambling or possibly climbing plants.[5]
- ^ Anderson, John M.; Anderson, Heidi M.; Cleal, Chris J. (2007). "Brief history of the gymnosperms: classification, biodiversity, phytogeography and ecology" (PDF). Strelitzia. 20: 1–280.
- ^ Hilton, J. & Bateman, R. M. (2006), "Pteridosperms are the backbone of seed-plant phylogeny", Journal of the Torrey Botanical Society, 33: 119–168, doi:10.3159/1095-5674(2006)133[119:PATBOS]2.0.CO;2
- ^ Laveine J.-P. (1986). "The size of the frond in the genus Alethopteris Sternberg (Pteridospermopsida, Carboniferous)". Geobios. 19: 49–56. doi:10.1016/s0016-6995(86)80035-3.
- ^ Wnuk C.; Pfefferkorn H. W. (1984). "The life habits and paleoecology of Middle Pennsylvanian medullosan pteridosperms based on an in situ assemblage from the Bernice Basin (Sullivan County, Pennsylvania, U.S.A.)". Review of Palaeobotany and Palynology. 41 (3–4): 329–351. doi:10.1016/0034-6667(84)90053-8.
- ^ Hamer J. J.; Rothwell G. W. (1988). "The vegetative structure of Medullosa endocentrica (Pteridospermopsida)". Canadian Journal of Botany. 66 (2): 375–387. doi:10.1139/b88-060.