The oldest group of vascular plants is still a hotly debated topic among botanists— especially as new plant fossils are found. It is believed that the first vascular plants were members of the division Rhyniophyta, which flourished around 400 million years ago but are now extinct. Still other scientists think the fossil record points to the club mosses (lycopods) as the most ancient—and in particular a genus of early lycopsid plants called Baragwanathia, found in Australian rocks from about 420 million years ago.