Medullosales
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. Their nearest still-living relatives are the cycads.
| Medullosales Temporal range: | |
|---|---|
| Neuropteris ovata Hoffmann, Late Carboniferous of northeastern Ohio. | |
| Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Division: | †Pteridospermatophyta |
| Order: | †Medullosales Corsin, 1960 |
| Families | |
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| Synonyms | |
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Most medullosales were small to medium-sized trees. The largest specimens were probably of genus Alethopteris, whose fronds could be 7 metres long 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. 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.