Assamiidae are a family of harvestmen with more than 400 described species. It is the third most diverse family of the suborder

Laniatores Laniatores is the largest suborder of the arachnid order Opiliones with over 4,000 described species worldwide. The majority of the species are highly dependent on humid environments and usually correlated with tropical and temperate forest habit ...

Name

The family name is derived from the

India India, officially the Republic of India ( Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the ...

n province

Assam Assam (; ) is a state in northeastern India, south of the eastern Himalayas along the Brahmaputra and Barak River valleys. Assam covers an area of . The state is bordered by Bhutan and Arunachal Pradesh to the north; Nagaland and Manipur ...

, where the type species of the type genus ('' Assamia westermanni'') was collected. (2007): Assamiidae Sørensen, 1884. In: Pinto-da-Rocha ''et al.'' 2007: 173ff

Description

These harvestmen range in body length from two to eight millimeters. The length of their legs ranges from four to forty millimeters, though they are usually long. Assamiidae are usually reddish brown to yellow with black mottling and reticulation. Some species have white drawings on the dorsal scutum.

Distribution

Assamiidae only occur in the

Old World The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by th ...

, and are completely absent from

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

and

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

, with most species found in

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and southern

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an ...

. Although they are also not found on the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

islands, the subfamily Dampetrinae has radiated in Australia,

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...

, and somewhat in

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

Subtaxa

Although Roewer established numerous subfamilies for this group, most of these are unsupported. There are at least five great groups, whose boundaries do not coincide with these subfamilies. :The Dampetrinae are endemic to Australia and New Guinea. :The Assamiinae occur mostly in

and

Nepal Nepal (; ne, नेपाल ), formerly the Federal Democratic Republic of Nepal ( ne, सङ्घीय लोकतान्त्रिक गणतन्त्र नेपाल ), is a landlocked country in South Asia. It is ma ...

. :The Trionyxellinae have a pseudonychium (a median

tarsal claw This glossary describes the terms used in formal descriptions of spiders; where applicable these terms are used in describing other arachnids. Links within the glossary are shown . Terms A Abdomen or opisthosoma: One of the two main body parts ...

on the third and fourth leg tarsi) and are found in India and

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

. :The Erecinae live in central Africa. :The small, blind Irumuinae dwell in

caves A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

and

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

. For a list of currently described species with the traditional groupings into subfamilies, see the List of Assamiidae species.

Relationships

The Assamidae are possibly the sister group to the

Gonyleptoidea Gonyleptoidea is the most diverse superfamily of the Grassatores. It includes around 2,500 species distributed in the tropics. They are characterized by the simplified male genitalia, with the glans free subapical in the truncus. Gonyleptoidea i ...

. The spiny funnel on the

penis A penis (plural ''penises'' or ''penes'' () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males d ...

is very similar to those of

Stygnopsidae 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". (2007): Sty ...

from

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

. Mello-Leitão erected the Trionyxellidae for four subfamilies of Assamiidae in 1949, but this was ignored by later authors.

Footnotes

References

* (eds.) (2007): Harvestmen - The Biology of Opiliones. ''Harvard University Press'' {{Taxonbar, from=Q142563 Harvestman families