Polydesmus is a genus of millipedes in the family Polydesmidae. With more than 200 species and subspecies, this genus is the largest in this family. This genus has a Palearctic distribution, with species found mainly in the Mediterranean region and in Europe west of the central Caucasus. This genus includes the notable species Polydesmus progressus, which exhibits sexual dimorphism in segment number: Whereas adult females of this species feature the 20 segments (counting the collum as the first segment and the telson as the last) usually observed on the order Polydesmida, the adult males feature only 19 segments.

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