We are now engaged in a detailed study of a variety of zosterophyll and lycopsid forms to help elucidate early diversification of the lycophyte clade of vascular plants (Gensel 1991, 1992; Gensel and Berry, 2001) and are developing a hypothesis about the evolution of rooting structures (possibly involving heterochrony) (Gensel et al. 2001; Gensel and Berry 2001).

Our study of plants now regarded as part of the second major clade of early vascular plants (the euphyllophytes), and the one that leads to seed plants, has provided considerable evidence of possible steps in the early evolution of leaves (Gensel, 1979; 1984; Trant and Gensel, 1985; Gensel ms in prep). Ongoing collaborations with a Chinese colleague have resulted in the description of disparate Early Devonian plants from China, which promote new thinking about both the timing and mode of appearance of basic plant structures (summarized in Hao and Gensel 2001).

A synthetic overview of the diversity of early land plants, and implications for evolutionary events, patterns or processes was published in Plant Life in the Devonian (Gensel and Andrews 1984). I also co-edited, with D. Edwards, a book entitled Plants Invade the land-Evolutionary and Environmental Perspectives (2001) which includes analyses, based on plant fossils and geological data, of the earliest phases of the history of plants.

See also the Paleobiology Database