Paleobotany, Phylogeny, and a Natural System of Classification

Summary In response to skeptics who feel that the contribution of paleobotany to phylogeny is minimal, I have presented a number of examples where the fossil plant record has played an important role in demonstrating origins and relationships of various plant groups. Work on Precambrian thallophytes is one area where knowledge of earliest plant forms is taking on a definite form. New finds on the origin and evolution of Devonian land plants are presenting a clearer picture of early vascular plant evolution. Existence of such plants as the Progymnospermopsida has made it possible to understand the steps leading to the origin of gymnosperms. We now have important new knowledge concerning the evolution of the seed habit, as well as subsequent seed plant evolution. These are but a few examples of the contribution of paleobotany to phylogeny. This increasing sophistication in understanding phylogenetic events is indispensible for a system of plant classification that reflects relationships. Such a system of classification, I maintain, is much more meaningful than any other.