The Ginkgophyta declined in diversity as the Cretaceous progressed, and by the Paleocene, "Ginkgo adiantoides" was the only "Ginkgo" species left in the Northern Hemisphere, while a markedly different (and poorly documented) form persisted in the Southern Hemisphere. Along with that of ferns, cycads, and cycadeoids, the species diversity in the genus "Ginkgo" drops through the Cretaceous, at the same time the flowering plants were on the rise; this supports the hypothesis that, over time, flowering plants with better adaptations to disturbance displaced "Ginkgo" and its associates.