Acer plant fossils from the famous Green River formation in Wyoming USA, these fossil specimens depict the winged seed part of the plant (many will know from today's modern equivalent as a 'helicopter' leaf). The fossils suggest that winged dispersal of seeds has clearly been a method used for many millions of years. The acer plant it's self, belongs to the maple family, which was a flora species that existed (and still does) during the Eocene period along with many other species of plants, however, as these specimens are only of the seed bearing part of the plant, the fossils measure approximately 1 cm in size and are on a matrix, which varies in size from specimen to specimen. These excellent pieces are well preserved and have been professionally prepped and clean so that as much of the fossil is visible as possible. They will come supplied in a small packet with an information label.