The Opiliones are an order of arachnids, colloquially known as harvestmen, harvesters, harvest spiders, or daddy longlegs. As of July 2024, over 6,650 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 Tetrophthalmi, which were named in 2014.
Gonyleptoidea is the most diverse superfamily of the Grassatores. It includes around 2,500 species distributed in the Neotropics. They are characterized by the simplified male genitalia, with the glans free subapical in the truncus.
Cosmetidae is a family of harvestmen in the suborder Laniatores. With over 700 species, it is one of the largest families in Opiliones. They are endemic of the New World with a Nearctic-Neotropical distribution where a large fraction of the diversity of Opiliones are represented by this single family. Cosmetidae have the northern extent of their range into the USA, where a small number species occur in the southern states. However, the family is especially diverse in Mexico, Central America and northern South America; especially the Andean realms. Their range also extends further south into Argentina and southern Brazil, but they are absent in Chile. Cosmetidae are prevalent in Amazonian region, but only relatively few also occur in Brazilian Atlantic Forest. Several species are also found in the Caribbean.
The Stygnopsidae are a small family of harvestmen, with almost all species found in Mexico.
Agoristenidae are a neotropical harvestman family of the Suborder Laniatores, in the superfamily Gonyleptoidea.
The Cranaidae are a family of neotropical harvestmen within the suborder Laniatores.
The Icaleptidae are a small family of neotropical harvestmen within the suborder Laniatores. Although only two species have been described, many more are probably to be discovered.
Escadabiidae is a small neotropical family of the harvestman infraorder Grassatores with six described species.
Kimulidae is a small neotropical family of the harvestman infraorder Grassatores with about thirty described species.
Samoidae is a family of the harvestman infraorder Grassatores with about fifty described species.
Biantidae is a family of the harvestman infraorder Grassatores with about 130 described species.
The Cladonychiidae are a small family of harvestman with about 33 described species, within the suborder Laniatores.
Yania is a genus of harvestmen from South America. Yania flavolimbata is the only species in the monotypic genus Yania. It was first described by Roewer, 1914.
Paranonychus brunneus is a species of armoured harvestman in the family Paranonychidae. It is found in eastern North America, ranging from Oregon through Washington, British Columbia, and Alaska.
Paranonychus is a genus of harvestman in the family Paranonychidae. There are three described species in Paranonychus. The Japanese species Paranonychus fuscus was originally described in its own genus as Mutsunonychus fuscus Suzuki 1976, but considered its own species and part of Paranonychus in later studies.
Neosiro exilis is a species of mite harvestman in the family Sironidae. It is found in North America.
Metasarcidae is a family of harvestmen, first described by Adriano B. Kury in 1994.
Metergininae is a subfamily of harvestmen in the family Cosmetidae.
Neoscotolemon is a genus of harvestmen in the superfamily Samooidea with seven described species. All species are found in the Greater Antilles and United States of America in Florida. An overview of the taxonomy was provided by Pérez-González et al. (2025).
Metapellobunus is a genus of harvestmen in the Grassatores with three described species. Two species are found in the Lesser Antilles, and one in Ecuador. An overview of the taxonomy was provided by Pérez-González et al. (2025).
