One of the most ancient fern families is the Osmundaceae, which includes the Royal Fern (Osmunda), Interrupted Fern (Claytosmunda), and Cinnamon Fern (Osmundastrum). All three of these genera are known from well-preserved fossils dating back to the Mesozoic era - some even as far back as the Triassic - and have remained remarkably unchanged since that time. The family also includes several extinct forms, the most common of which is the plant known as Todites. Large sterile fronds (Cladophlebis), tree fern-like stems (Osmundacaulis), and the distinctive spore-bearing fronds (Todites) are often found separately but have also been discovered attached to the same plant. This has allowed paleobotanists to reconstruct a “whole-plant concept,” combining the individual fossil parts into a single organism. In a reversal of the situation with Coniopteris, Todites appears to have been a tree fern, whereas most modern Osmundaceae are ground ferns; though the modern Todea barbara also forms a short trunk. Todites likely grew in the understory of wet Jurassic and Cretaceous forests.