The Archidesmida is an extinct
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
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 known from fossils from the
Devonian period
The Devonian ( ) is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.3 million years from the end of the preceding Silurian period at million years ago ( Ma), to the beginning of the succeeding C ...
of Europe and North America. Archidesmidans have broad flat keels (
paranota) extending from their body segments, and a modified pair of legs on the 8th segment that may have been involved in mating, similar to 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 of living millipedes which insert sperm into females. Alternately, the modified legs may have been used to grasp onto partners during mating.
References
Prehistoric arthropod orders
Millipede orders
Devonian myriapods
Late Devonian animals
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