Zosterophylls are an extinct group of early vascular plants that lived during the Silurian and Devonian periods. They are significant in paleobotany and evolutionary biology for their role in understanding the evolution of vascular plants, the transition from aquatic to terrestrial ecosystems, and the origins of modern plant lineages.
Reference: Kenrick, P., & Crane, P. R. (1997). “The Origin and Early Diversification of Land Plants: A Cladistic Study.” Smithsonian Institution Press.