Dicellophilus is a genus of soil centipedes in the family Mecistocephalidae. This genus was introduced by the American biologist Orator F. Cook in 1896 to contain the species D. limatus,[1] which he explicitly designated as the type species.[2] This genus contains four species and is notable for the highly disjunct geographic distribution of these species.[3]
The four species in this genus are each found in one of three limited and unusually disjunct areas. The species D. carniolensis is limited to central Europe, the species D. pulcher is limited to the island of Honshu in Japan, and the species D. limatus and D. anomalus are both limited to the west coast of the United States. The range of each species is no more than 1,300 km in maximum diameter. These species live mostly in montane forests with moderate temperatures. While the ranges of these species all fall within a narrow band of latitude (about 35–45 °N), they are maximally separated in terms of longitude. No other group of centipedes, and no terrestrial animals in the Northern Hemisphere, are known to exhibit such a peculiar geographic distribution.
A phylogenetic analysis of the family Mecistocephalidae using morphological features places this genus in the subfamily Dicellophilinae along with the genera Anarrup and Proterotaiwanella. This analysis also places Dicellophilus in a clade with Anarrup as a closely related sister group.[4] A phylogenetic analysis of the genus Dicellophilus based on morphological evidence confirms the monophyly of the genus and places the two North American species, D. anomalus and D. limatus, together in a clade. This analysis also places this North American clade inside another clade along with the Japanese species D. pulcher in a phylogenetic tree.
Centipedes in this genus range from 5 cm to 7 cm in length and have 41 to 45 pairs of legs, with the number of legs invariant within each species.[5] The species D. anomalus and D. pulcher have 41 leg pairs, the species D. carniolensis has 43 pairs, and the type species D. limatus has 45 pairs. In this genus, the body tapers towards the posterior and ranges from pale yellow to orange brown, without dark patches, but the head and forcipular segment is darker than the rest of the body. The antennae taper towards the distal ends. These species feature a labrum with longitudinal folds. The ultimate legs feature a ventral pore that is distinctly larger than all the other pores and an apical tubercle with a few small spines.[6]
This genus includes four species: