Order Dioales Doweld 2001 (cycads)
Full reference: A. B. Doweld. 2001. Prosyllabus Tracheophytorum. Tentamen Systematis Plantarum Vascularium.
Parent taxon: Cycadopsida according to A. B. Doweld 2001
Sister taxa: Boweniaceae, Crassofilicites, Cycadales, Deltolepis, Drepanozamites, Gnetales, Lagenostomales, Manebachia, Marantoidea, Orthogoniopteris, Pteridospermales, Stangeriaceae, Strangerites, Trigonocarpales, Welwitschiales
Subtaxa: Dioaceae
Distribution: found only at Hamilton Bay, Kupreanof Island - 7565 (55) (Eocene of Alaska)