Produced by the Population Genetics and Evolution class, Furman University

The Devonian: Archaeopteris
The plant life of the early Devonian is characterized by several radiations of primitive vascular plants like the rhyniophytes and zosterophyllophytes. Through the period, these plants evolved into taller and taller vegetation, with the oldest woody trees evolving in the mid-Devonian - typified by the Gilboa forests of Wattieza trees that grew as tall as 8m (Wikipedia 2010a). By the end of the Devonian, significant forests had evolved (Murphy 2005). One of the principal canopy trees of these first forests was the progymnosperm Archaeopteris; a genus of tall (20m) trees that is found on every land mass of the Devonian Period and produced spores instead of seeds (Wikipedia 2010b). Forests had a dramatic effect on terrestrial and aquatic habitats, adding deep, rich organic inputs to soils, stabilizing soils and streambanks, and moderating stream volumes by reducing surface flow. In short, the evolution of the forest biome begins with these Wattieza and Archaeopteris forests.

Page by Wade Worthen
Archaeopteris leaf. . Photo from: University of London

Murphy D. 2005. The first forests. Devonian Times. Accessed February 27, 2010.

Wikipedia. 2010a. Wattieza. Accessed February 27, 2010.

Wikipedia. 2010b. Archaeopteris. Accessed February 27, 2010.