*Joel Hallan's Biology Catalog (2005)*Harvestman: Order Opiliones Diagnostic photographs and information on North American harvestmen*Harvestman: Order Opiliones Diagnostic photographs and information on European harvestmen*University of Aberdeen: The Rhynie Chert Harvestmen (fossils)*National Museum page Classification of Opiliones A synoptic taxonomic arrangement of the order Opiliones, down to family-group level, including some photos of the families