Gymnosperms

The gymnosperms produce seeds that have no seed coat. The seed is often protected by a scale. They include the conifers, yews, gingkoes, and the cycads. The earliest gymnosperms appear in the Devonian Period and the group diversified into various forms. The fossil gymnosperms known from Mazon Creek include:

cordaianthus, male catkins
cordaicarpus, seed
cordaites, leaf
Artisia, pith cast of stem