To find strong physical evidence that the moss-like liverwort was indeed the oldest land plant, Patricia Gensel, professor of biology, had to get creative.
Gensel and colleagues at the University of Wisconsin and Illinois State University wanted to compare modern liverworts to plant fossils found in rocks dating back at least four hundred-million years. But the plant fossils were really just scraps, or "small tubular pieces and parts of what we call cuticle," Gensel says. To make a true comparison Gensel and colleagues turned the modern liverworts into scraps by rotting them in soil for weeks. The resulting remnants were almost identical to the four-hundred-million-year-old fossils.
The findings were published July 20, 2004, in the Proceedings of the National Academy of Sciences.
