However, some paleontologists argue that the "rootlets" were true roots, with a complex branching structure and root hairs, comparable to the roots of the closest living relative of Lepidodendron, the quillworts (genus Isoetes).
Some paleontologists believe that the "rootlets" are genuine roots with a complicated branching system and root hairs, comparable to the roots of the nearest living relative of Lepidodendron, represented by the genus Isoetes.