Polydesmidae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

millipede Millipedes (originating from the Latin , "thousand", and , "foot") are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derive ...

s in the order

Polydesmida Polydesmida (from the Greek ''poly'' "many" and ''desmos'' "bond") is the largest order of millipedes, with more than 5,000 species, including all the millipedes reported to produce hydrogen cyanide (HCN). This order is also the most diverse of ...

. This family includes more than 240 species in more than 30 genera. These millipedes have a mostly

Holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical reg ...

distribution that extends south not only to

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

and

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

but also as far as

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

. Most species are found in the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

region.

Description

These millipedes range from 4 mm to 30 mm in length. Colors range from pitch black through reddish or brownish to pallid and are rarely vivid. The collum is small, in the shape of a transverse oval, with a smooth anterior margin. The paranota are simple but usually well developed and dentate laterally. This family includes the notable species '' Polydesmus progressus'', which exhibits

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

in segment number: Whereas adult females of this species feature the 20 segments (counting the collum as the first segment and the

telson The telson () is the hindmost division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment (biology), segment of the arthropod body, or an additional division that is not a true segm ...

as the last) usually observed on the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

, the adult males feature only 19 segments.

Genera

*'' Antrochodus'' *'' Archipolydesmus '' *'' Basicentrus '' *'' Bhutanodesmus '' *'' Bidentogon '' *'' Bosniodesmus '' *'' Bosporodesmus '' *'' Brachydesmus '' *'' Brembosoma '' *'' Calianotus '' *'' Chromobrachydesmus'' *'' Cretodesmus'' *'' Dixidesmus '' *'' Epanerchodus '' *'' Eumastigonodesmus'' *'' Goniodesmus '' *'' Haplobrachidesmus'' *'' Haplocookia '' *'' Heterocookia '' *'' Himalodesmus '' *'' Hispaniodesmus '' *'' Huzichodus '' *''

Jaxartes The Syr Darya ( ),; ; ; ; ; /. historically known as the Jaxartes ( , ), is a river in Central Asia. The name, which is Persian, literally means ''Syr Sea'' or ''Syr River''. It originates in the Tian Shan Mountains in Kyrgyzstan and eastern ...

'' *'' Kirgisdesmus '' *'' Leptobrachydesmus'' *'' Lophobrachydesmus '' *'' Mastigonodesmus '' *'' Mastuchus '' *'' Merioceratium '' *'' Niponchodus '' *'' Nipponesmus '' *'' Nomarchus '' *'' Pacidesmus '' *'' Peltogonopus '' *'' Perapolydesmus '' *'' Polydesmus '' *'' Prionomatis '' *'' Propolydesmus '' *'' Pseudopolydesmus '' *'' Retrorsia '' *'' Riuerchodus '' *'' Sardodesmus '' *'' Schedoleiodesmus'' *'' Schizobrachydesmus '' *'' Schizomeritius'' *'' Schizoturanius'' *'' Scytonotus'' *'' Serradium'' *'' Spanobrachium'' *'' Speodesmus'' *'' Stylobrachydesmus'' *'' Telopoditius'' *'' Tolosanius'' *'' Trachynotus'' *'' Troglobrachydesmus'' *'' Turanodesmus'' *'' Uniramidesmus'' *'' Usbekodesmus'' *'' Utadesmus''

References

Polydesmida Millipede families {{Millipede-stub