The Ceratolasmatidae are a family of

harvestmen The Opiliones (formerly Phalangida) are an Order (biology), order of arachnids, Common name, colloquially known as harvestmen, harvesters, harvest spiders, or daddy longlegs (see below). , over 6,650 species of harvestmen have been discovered w ...

with eleven described species. The

monophyly In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent comm ...

of this family is questionable; it is composed of three possibly monophyletic groups: (2007): Ceratolasmatidae Shear, 1986. In: Pinto-da-Rocha ''et al.'' 2007: 134ff * ''Ceratolasma'' and ''Acuclavella'' are four to six millimeters long, with moderately short legs and short

pedipalp Pedipalps (commonly shortened to palps or palpi) are the secondary pair of forward appendages among Chelicerata, chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to ...

s. These two genera are closely related to '' Ischyropsalis'' (

Ischyropsalididae Ischyropsalididae is a family of harvestmen The Opiliones (formerly Phalangida) are an Order (biology), order of arachnids, Common name, colloquially known as harvestmen, harvesters, harvest spiders, or daddy longlegs (see below). , over 6,6 ...

). * ''Hesperonemastoma'' species range from one to two millimeters in body length. They have similarities to '' Nemastoma'', which occurs in the

Old World The "Old World" () is a term for Afro-Eurasia coined by Europeans after 1493, when they became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia in the Eastern Hemisphere, previously ...

(''hespero'' = "west" alludes to the occurrence in the

New World The term "New World" is used to describe the majority of lands of Earth's Western Hemisphere, particularly the Americas, and sometimes Oceania."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: ...

). It seems to be more closely related to ''

Taracus ''Taracus'' is a genus of harvestman, or Opiliones, typically found living in limestone and lava caves in the United States. They grow to a size of . Taxonomy ''Taracus'' contains the following species, per World Catalog of Opiliones. Of the 14 ...

'' (

Sabaconidae ''Sabacon'' is a genus of the monotypic harvestman family Sabaconidae, with 59 species (as of 2023). Description Species of the genus ''Sabacon'' have usually thickened pedipalps with stiff, fine hairs, which is unique among harvestmen. Althoug ...

) than to ''Ceratolasma''. * ''Crosbycus'' has a body length of less than one millimeter. The

s are long and very thin. Its moderately long legs are densely covered with

setae In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae ...

, spikes and

trichome Trichomes (; ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...

s. ''Crosbycus'' should possibly be placed in its own family.

Distribution

The family is restricted to

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, from

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

. ''Crosbycus'' is also found in

Eastern Asia East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of China, Japan, South Korea, and Taiwan ...

Name

The genus name is a combination of

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

''keras'' "horn" and the ending ''-lasma'', referring to the similarity of genera such as '' Ortholasma'' and '' Dendrolasma'' (

Nemastomatidae The Nemastomatidae are a family of harvestmen with about 170 described species in 16 recent genera. Several fossil species and genera are known. Unlike some related currently recognized families, the Nemastomatidae are monophyletic. (2007): Nema ...

Species

* '' Acuclavella'' Shear, 1986 ** '' Acuclavella cosmetoides'' Shear, 1986 --

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

** '' Acuclavella merickeli'' Shear, 1986 -- Idaho ** '' Acuclavella quattuor'' Shear, 1986 -- Idaho ** '' Acuclavella shoshone'' Shear, 1986 -- Idaho * '' Ceratolasma'' Goodnight & Goodnight, 1942 ** '' Ceratolasma tricantha'' Goodnight & Goodnight, 1942 --

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

* '' Crosbycus'' Roewer, 1914 ** '' Crosbycus dasycnemus'' (Crosby, 1911) -- British Columbia and China * ''

Hesperonemastoma ''Hesperonemastoma'' is a genus of harvestmen in the family Taracidae Taracidae is a family of harvestmen in the order Opiliones The Opiliones (formerly Phalangida) are an Order (biology), order of arachnids, Common name, colloquially know ...

'' Gruber, 1970 ** '' Hesperonemastoma pallidimaculosum'' (Goodnight & Goodnight, 1945) --

Alabama Alabama ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South, Deep Southern regions of the United States. It borders Tennessee to the north, Georgia (U.S. state), Georgia to the east, Florida and the Gu ...

** '' Hesperonemastoma inops'' (Packard, 1884) -- cave in

Kentucky Kentucky (, ), officially the Commonwealth of Kentucky, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Illinois, Indiana, and Ohio to the north, West Virginia to the ...

** '' Hesperonemastoma modestum'' (Banks, 1894) -- western United States ** '' Hesperonemastoma packardi'' (Roewer, 1914) -- cave in

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

** '' Hesperonemastoma kepharti'' (Crosby & Bishop, 1924) --

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

Footnotes

References

* Joel Hallan's Biology Catalog
Ceratolasmatidae
* (eds.) (2007): Harvestmen - The Biology of Opiliones. ''Harvard University Press'' {{Taxonbar, from=Q2946374 Harvestman families Taxa named by William Shear