petrified prehistorical ferns frond imprint on stone

age and archaeological archaeology archeologic archeological archeology backdrop background branches earth era evolution extinct fern ferns foliage fossil fossilised fossilized frond geologic geological geology historic historical history imprint jurassic leaves mesozoic natural nature palaeontologic palaeontology palaeozoic paleontologic paleontology paleozoic period petrifaction petrification petrified plants prehistoric prehistorical prehistory print rock stone texture twigs