Aprosphylosoma darceneae is a species of cylindrical julidan millipede found only in the U.S. state of Oregon and comprising the sole species of the family Aprosphylosomatidae. It is known from only a single known specimen collected from Oregon Caves National Monument in 1956 that measures approximately 16mm long and 1 mm wide, possessing 59 body segments. The first pair of legs are extremely reduced into non-jointed, peg-like structures. The body color is yellowish brown with darker brown mottling on the dorsal surface, and the legs are white.[1] [2]
Aprosphylosoma was originally classified as a new distinct subfamily ("Aprosphylosomatinae") of the family Nemasomatidae.[1] Subsequent cladistic analysis placed Aprosphylosoma into the family Paeromopodidae. Further taxonomic study elevated the genus to its own distinct family, Aprosphylosomatidae, which together with Paeromopodidae constitutes the superfamily Paeromopodoidea.[2]