Fossilised Tree Fern

Plants that flourished on earth millions of years ago are perfectly preserved as fossils. In fossilised wood, the tissue of ancient trees is completely replaced by minerals, converting trunks and branches into stone. In some cases, the cell structure is so perfectly preserved that it resembles microscopic stem sections of modern plants. Ferns first appear in the fossil record 360 million years ago in the late Devonian period but many of the current families and species did not appear until roughly 145 million years ago in the early Cretaceous period.