Sawdoniaceae
Sawdoniaceae is a family of extinct zosterophylls. The zosterophylls were among the first vascular plants in the fossil record, and are considered to share an ancestor with the living lycophytes. The family is recognized by some sources, and placed in the Sawdoniales. Other sources do not recognize the family, and place some of its members in the family Gosslingiaceae.
Genera
Genera that have been placed in this family by Kenrick and Crane in 1997 are shown in the table below, along with their treatment by Hao and Xue in 2013.| Genus | Hao & Xue |
| †Crenaticaulis Banks & Davis | Gosslingiaceae |
| †Sawdonia Hueber | Gosslingiaceae |
| †Konioria Zdebska | incertae sedis |
| †Anisophyton | unplaced as to family |
| †Deheubarthia | unplaced as to family |
| †Serrulacaulis | unplaced as to family |