A Prototaxites fossil in the desert of Saudi Arabia. New findings now seem to confirm it is a fungus. Credit: Reprinted from Review of Paleobotany and Palynology, Vol. 116, "Rotted wood--alga--fungus: the history and life of Prototaxites Dawson 1959, by Francis Hueber, p. 146, Smithsonian Institution, Copyright 2001, with permission from Elsevier