| Sawdoniales Temporal range:
| |
|---|---|
| |
| Sawdonia ornata with ground creeping roots (A); lateral reniform sporangia (B) | |
| |
| Sawdonia ornata | |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Lycophytes |
| Plesion: | †Zosterophylls |
| Order: | †Sawdoniales |
| Families | |
The Sawdoniales are an order or plesion of extinct zosterophylls. The zosterophylls were among the first vascular plants in the fossil record, and share an ancestor with the living lycophytes. The group has been divided up in various ways. In their major cladistic study of early land plants, Kenrick and Crane placed most of the zosterophylls in the Sawdoniales (which they treated as a plesion).[1]
Like other zosterophylls, members of the Sawdoniales bore lateral, reniform sporangia. They branched dichotomously, and grew at the ends by unrolling (circinate vernation). Some had smooth stems, others were covered in small spines; fungal bodies have been reported in some spines.[2]
- ^ Kenrick & Crane (1997), p. 12.
- ^ Rayner, R.J. (1983). "New observations on Sawdonia ornata from Scotland". Transactions of the Royal Society of Edinburgh. 74 (2): 79–93. doi:10.1017/s026359330001018x.
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