Slime mold beetles of the genus Anisotoma (Leiodidae): classification and evolution

Leiodid beetles of the genus Anisotoma are redefined and reclassified, based on a cladistic analysis of the world fauna, and evolutionary and biogeographic hypotheses are discussed. Agathidium is the probable sister group of Anisotoma. Anisotoma consists of six monophyletic species groups, involving thirty‐five known species, including thirteen new species: bifoveata, maculata, latustriata, sinuosa, campbelli, exigua, tenuiucida, hidalgoensis, montana, colima, autlanensis, scopula and reticulonota. Speciation may occur at a rapid rate in Anisotoma , between 10 000 and 1 000 000 years. Anisotoma arose in North America, from a hypothetical Holarctic common ancestor of Anisotoma and Agathidium , and spread into Palearctic and Central American regions. Taxonomic history, natural history, and methods are briefly discussed, and the following given where appropriate: synonymies, diagnoses, descriptions, natural histories, distributions, remarks, materials examined, maps, keys to species and species groups, illustrations, and habitus drawings. Lectotypes are designated for Horn, LeConte, Melsheimer and Portevin species as needed. A. obsoleta (Horn) is renamed A. homi due to preoccupation. The Japanese genus Eucyrta Portevin is reduced to a synonym of Anisotoma.