Arrup

Arrup is a genus of soil centipedes in the family Mecistocephalidae. This genus contains sixteen species. These centipedes are found mainly in temperate regions of East Asia with some species found in Central Asia and California. Most species in this genus are soil-dwellers, but the Japanese species Arrup akiyoshiensis was discovered in a cave and might be a troglobiont.

== Taxonomy and Phylogeny == The American biologist Ralph V. Chamberlin first proposed this genus in 1912 to contain a newly discovered centipede, Arrup pylorus, which he designated as the type species. In 2003, a cladistic analysis of the family Mecistocephalidae based on morphology placed the genus Arrup in the subfamily Arrupinae, along with the genera Agnostrup, Nannarrup, and Partygarrupius. Further cladistic analysis of the subfamily Arrupinae based on morphology placed the genus Arrup in a clade with Nannarrup as a closely related sister group. This analysis also placed this clade inside another clade with Agnostrup as a sister group in the same branch of a phylogenetic tree. In 2024, however, a phylogenetic analysis based on molecular data placed Arrup by itself on the most basal branch in a phylogenetic tree of the family Mecistocephilidae, with a sister group including Agnostgrup and Nannarrup together in a separate clade.