|A Cycadeoid, showing an "inflorescence" in the top-right|
|Life restoration of Williamsonia|
|Unrecognized taxon ():||Bennettitales|
They first appeared in the Permian period and became extinct in most places toward the end of the Cretaceous. Bennettitales are among the most common Mesozoic seed plants. They looked like shrubs or cycads.
Although the leaves of the bennettitales looked like that of cycads, they had more complex flower-like reproductive organs. So some of them were probably pollinated by insects.
References[change | change source]
- Arens NC, Stromberg C, Thompson A. "Introduction to the Bennettitales". University of California Museum of Paleontology. 
- Peñalver E, Arillo A, Pérez-de la Fuente R, Riccio ML, Delclòs X, Barrón E, Grimaldi DA (2015). "Long-proboscid flies as pollinators of Cretaceous gymnosperms". Current Biology. 25 (14): 1917–23. doi:10.1016/j.cub.2015.05.062. PMID 26166781.