Cycadeoidales

Abstract

Foliage generally attributed to Cycadophytes (cycads and cycadeoids) has been observed from the Permian. In the Mesozoic there are several remains of foliage considered to be definitely of cycads and cycadeoids (they cannot be separated by morphological features alone). The leaves had characteristic leathery texture due to heavy cutinization of the epidermis, and abundant supporting tissue within the lamina and around the veins. This is because the foliage was exposed to arid and semi-arid climates for 200 or more million years and, therefore, could survive the adverse conditions of the Permian much better than the Pteridosperms (Arnold 1953). These tissues are able to resist decay, the compressed foliage often retains part of the cutinized epidermis which can be separated from the rock and studied (microscopically).