The Stygnopsidae are a small family of harvestmen, with almost all species found in Mexico. Name The name of the type genus Stygnopsis is combined from the genus Stygnus (Stygnidae) and Ancient Greek opsis, "looks like". Description The body length of these harvestmen ranges from 2.5 (Karos) to 7 mm (Hoplobunus). Their color ranges from dark brown to black, with much lighter appendages. Cave-dwelling species are pale light brown. Distribution As in other Laniatores, most species have narrow distributions. Almost all species occur in Mexico, with some found in the southern USA (Hoplobunus), and Guatemala, El Salvador and Belize (Paramitraceras). Relationships Epedanidae could be the sister group to Gonyleptoidea sensu lato (including the Assamiidae), with the Stygnopsidae the sister group to the rest of Gonyleptoidea. Although they reach into the Nearctic, they are more closely related to neotropical harvestmen. Species Hoplobunus Banks, 1900 Hoplobunus apoalensis Goodnight & Goodnight, 1973 — Mexico Hoplobunus barretti Banks, 1900 — Mexico Hoplobunus boneti (Goodnight & Goodnight, 1942) — cave, Mexico Hoplobunus madlae Goodnight & Goodnight, 1967 — Texas Hoplobunus mexicanus (Roewer, 1915) — Mexico Hoplobunus mexicanus (Sørensen, 1932) — praeoccuppied; Mexico Hoplobunus oaxacensis Goodnight & Goodnight, 1973 — Mexico Hoplobunus osorioi (Goodnight & Goodnight, 1944) — Mexico Hoplobunus planus Goodnight & Goodnight, 1973 — Mexico Hoplobunus queretarius Silhavy 1974 — Mexico Hoplobunus russelli Goodnight & Goodnight, 1967 — Texas Hoplobunus spinooculorum Goodnight & Goodnight, 1973 — Mexico Hoplobunus zullinii Silhavy 1977 — Mexico Karos Goodnight & Goodnight, 1944 — Mexico Karos barbarikos Goodnight & Goodnight, 1944 Karos brignolii Silhavy 1974 Karos depressus Goodnight & Goodnight, 1971 Karos dybasi (Goodnight & Goodnight, 1947) Karos foliorum (Goodnight & Goodnight, 1945) Karos gratiosus Goodnight & Goodnight, 1971 Karos parvus Goodnight & Goodnight, 1971 Karos projectus Goodnight & Goodnight, 1971 Karos rugosus Goodnight & Goodnight, 1971 Karos tuberculatus (Goodnight & Goodnight, 1944) Karos unispinosus (Goodnight & Goodnight, 1946) Mexotroglinus Silhavy, 1977 Mexotroglinus sbordonii Silhavy, 1977 — Mexico Paramitraceras F. O. P-Cambridge, 1905 Paramitraceras femoralis Goodnight & Goodnight, 1953 — Mexico Paramitraceras granulatus F. O. Pickard-Cambridge, 1905 — Guatemala, El Salvador, Mexico Paramitraceras hispidulus F. O. Pickard-Cambridge, 1905 — Guatemala, Belize, Mexico Sbordonia Silhavy 1977 — Mexico Sbordonia armigera Silhavy 1977 Sbordonia parvula (Goodnight & Goodnight, 1953) Stygnopsis Sørensen, 1902 — Mexico Stygnopsis robusta (Goodnight & Goodnight, 1971) Stygnopsis valida (Sørensen, 1884) Tampiconus Roewer, 1949 Tampiconus philippii Roewer, 1949 — Mexico Troglostygnopsis Silhavy, 1974 — Mexico Troglostygnopsis anophthalma Silhavy,