Spirobolida is an

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 ...

of "round-backed"

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 containing approximately 500 species in 12

families Family (from ) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictability, structure, and safety as ...

. Its members are distinguished by the presence of a "pronounced suture that runs "vertically down the front of the head". Most of the species live in the

tropics The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

, and many are brightly coloured. Mature males have two pairs of modified legs, the

gonopod Gonopods are specialized appendages of various arthropods used in reproduction or egg-laying. In males, they facilitate the transfer of sperm from male to female during mating, and thus are a type of intromittent organ. In crustaceans and millipe ...

s, consisting of the 8th and 9th leg pair: the posterior gonopods are used in sperm-transfer while the anterior gonopods are fused into a single plate-like structure. Aphistogoniulus jeekeli holotype gonopods 02

Aphistogoniulus jeekeli holotype gonopods 02

The families are divided into two suborders: Suborder Spirobolidea * Allopocockiidae * Atopetholidae *

Floridobolidae ''Floridobolus'' is a genus of millipedes commonly known as Florida scrub millipedes containing three described species: ''Floridobolus penneri'', ''F. orini'', and ''F. floydi''; the latter two described in 2014. All three species are endemic to ...

* Hoffmanobolidae *

Messicobolidae The family Messicobolidae is one of the smaller families of millipedes in the order Spirobolida (fewer than 30 described species). In general appearance, messicobolids are medium to large size spirobolids and are often brightly colored. Messicob ...

Pseudospirobolellidae Pseudospirobolellidae, is a family of round-backed millipedes of the order Spirobolida Spirobolida is an Order (biology), order of "round-backed" millipedes containing approximately 500 species in 12 family (biology), families. Its members ar ...

Rhinocricidae Rhinocricidae is a family of millipedes, that occurs disjunctly in Malesia and neighbouring parts of Australasia and in the Neotropics The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physic ...

* Spirobolellidae *

Spirobolidae Spirobolidae is a family of millipedes in the order Spirobolida. The family consists of several genera with numerous species, and is commonly divided into the subfamilies Spirobolinae and Tylobolinae. Classification Subfamily Spirobolinae * '' ...

* Typhlobolellidae Suborder Trigoniulidea *

Pachybolidae Pachybolidae is a family of round-backed millipedes of the order Spirobolida. The family includes 49 different genera. Two subfamilies are recognized. Subfamilies * Pachybolinae * Spiromiminae Genera *'' Alluviobolus'' *'' Aphistogoniulus'' * ...

Trigoniulidae Trigoniulidae, is a family of round-backed millipedes of the order Spirobolida. The family includes 171 species belongs to 25 genera. Genera *'' Acanthiulus'' *'' Ainigmabolus'' *'' Apeuthes'' *'' Cairibolus'' *'' Chersastus'' *'' Cingalobolus ...

Select species

*''

Narceus americanus ''Narceus americanus'' is a large millipede of eastern North America. Common names include American giant millipede, worm millipede, and iron worm. It inhabits the eastern seaboard of North America west to Georgetown, Texas, north of the Ottine ...

'', a commonly seen species in eastern North America *'' Crurifarcimen vagans'', the "wandering leg sausage" *'' Anadenobolus monilicornis'', the yellow-banded millipede *''

Eucarlia ''Eucarlia'' is a genus of spirobolidan millipedes containing six species; most of which are endemic to the island nation of Seychelles, and one native to the Indonesian island of Sulawesi. Four of the Seychelles species have been assessed by t ...

'', a genus of threatened Indo-Pacific millipedes

References

External links

* * * Millipede orders Taxa named by Charles Harvey Bollman {{Millipede-stub