Class Diplopoda Rank Family | ||
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Similar Polydesmida, Dalodesmidae, Pyrgodesmidae, Eutrichodesmus, Siphonocryptida | ||
Ammodesmidae is a family of small millipedes endemic to Africa, containing seven species in two genera. Ammodesmids range from 1.4 to 5.0 mm (0.055 to 0.197 in) long with 18 or 19 body segments in both sexes, and are capable of rolling into a tight sphere.
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Ammodesmidae contains two genera: Ammodesmus, with three species known from West Africa and the Democratic Republic of Congo, and Elassystremma, with four species known from East Africa. Adult Ammodesmus range from 1.4–2 mm in length, and adult males possess a last pair of legs strongly modified: bearing long whip-like bristles (setae) and with vestigial claws. Males of the genus Elassystremma lack the modified rear legs, and are larger, from 3.3–5 mm.
Ammodesmus
The genus Ammodesmus was named in 1896 by Orator F. Cook in the description of Ammodesmus granum. The genus was thought restricted to West Africa (Guinea, Liberia and Ivory Coast) until the 2015 description of A. congoensis from the Democratic Republic of the Congo. A. congoensis differs from the other two speciesin lacking ozopores (defensive glands), and has conspicuous sexual dimorphism, with females bearing sparse, long setae.
Elassystremma
The genus Elassystremma was established in 1981 by Richard L. Hoffman and K. M. Howell. Four species are known, occurring in Kenya, Tanzania, and Malawi.