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

摘要

Abstract.Leiodid beetles of the genusAnisotomaare redefined and reclassified, based on a cladistic analysis of the world fauna, and evolutionary and biogeographic hypotheses are discussed.Agathidiumis the probable sister group ofAnisotoma. Anisotomaconsists 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, scopulaandreticulonota.Speciation may occur at a rapid rate inAnisotoma, between 10 000 and 1 000 000 years.Anisotomaarose in North America, from a hypothetical Holarctic common ancestor ofAnisotomaandAgathidium, 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 renamedA. homidue to preoccupation. The Japanese genusEucyrtaPortevin is reduced to a synonym ofAnisotom