Cycads were an abundant component of the flora in the Mesozoic. During the Triassic and Jurassic, the time of their greatest diversity, cycads made up 20% of the world flora. For this reason the Mesozoic, and especially the Jurassic, is often referred to as the “Age of Cycads”. During this time, they were an important component of the vegetation, not simply in numbers of species, but in size and number of individuals. Cycads were the trees and shrubs which, along with the conifers and Ginkgoales, dominated the Mesozoic forests.
Cycads evolved 3 basic architectural strategies for making their seeds available to large browsing animals: (1) individual seeds attached to long, flexible sporophylls, (2) upright cones borne at the stem apex, and (3) cones suspended beneath the leaf crown on a short stalk. (Source of photos: The Cycad Newsletter 30(1) March 2007)
