The Opiliones (/ˈoʊpɪliːˈoʊniːs/; formerly Phalangida) are an order of arachnids commonly known as harvestmen. As of December 2011, over 6,500 species of harvestmen have been discovered worldwide, although the total number of extant species may exceed 10,000. The order Opiliones includes five suborders: Cyphophthalmi, Eupnoi, Dyspnoi, Laniatores, and the recently named Tetrophthalmi. With the exception of the Dyspnoi (which are restricted to North America and Eurasia), representatives of each can be found on every continent except Antarctica. Well-preserved fossils have been found in the 400-million-year-old Rhynie cherts of Scotland, and 305-million-year-old rocks in France, which look surprisingly modern, indicating that their basic body plan appeared very early on, and, at least in some