Paleontology and geology
During the Carboniferous, Virginia was equatorial and the warm seas supported abundant life and the deposition of limy sediments. Today, the limestones produced from these sediments are rich in fossils of bryozoans and relatives of sea urchins and sand dollars. On land, coastal swamps formed along what is now the Appalachian Plateau. Tall scale trees (lycophytes), horsetail rushes, and other plants grew in abundance in these swampy lowlands, eventually producing vast coal seams in southwestern Virginia.