A cut and polished slab of Rhynie chert showing roots and stems of early fossil land plants Rhynia and Aglaophyton. 380 Million Years Old. Devonian Period. Old Red Sandstone. . Locality Rhynie, Aberdeenshire, Scotland, UK. Slab measures approx 75mm x 65mm . Rhynie chert was formed in the hot waters around the Geysers, Like the geysers in Yellowstone National park. Wyoming, U.S.A. This siliceous rock produced by the hot springs has revealed many early land plants and animals like fairy shrimps, early spiders, mites, springtails and myriapods . More Pics Below !.....