|Upper Jurassic to Upper Cretaceous|
|161 to 65 million years|
The representatives have a massive, little branched trunk. The leaves are usually pinnate and tufted at the end of the stems.
The cone-like reproductive organs sit between the leaf bases. They mostly contain both female and male organs, so they are bisporangiate. Reports of monosporangiate cones are unlikely to be accurate. The sporophylls and the scales between them are arranged parallel to one another. The ovules and seeds show ribs in cross section, which widen like wings towards the tip of the seed. The sarcotesta of the seed coat consists of cells elongated in the longitudinal direction.
The family includes the following genera:
- Thomas N. Taylor, Edith L. Taylor, Michael Krings: Paleobotany. The Biology and Evolution of Fossil Plants . Second Edition, Academic Press 2009, ISBN 978-0-12-373972-8 , pp. 725-732.
- KR Spurs: The Morphology of Gymnosperms . Hutchinson University Library, London 1965. (without ISBN), pp. 92-97.
- Gar W. Rothwell, Ruth A. Stockey: Anatomically preserved Cycadeoidea (Cycadeoidaceae), with a reevaluation of systematic characters for the seed cones of Bennettitales . American Journal of Botany, 2002, Vol. 89, pp. 1447-1458.