A systematic review of amphizoid beetles lAmphizoidaec Coleopterar and their phylogenetic relationships to other adephaga

Rediscovery of type material for Amphizoa davidi Lucas, 1882, the only known Palaearctic amphizoid, is reported, with a lectotype designated, and the type area emended (from Tibet to Szechwan Province, China). A key is provided for identification of adults of the four known amphizoid species. Form and structure, geographical and habitat distributions, and geographical relations with other taxa are described and illustrated for each species. Amphizoa carinata Edwards, 1951, is recognized as a junior synonym of A. lecontei Matthews, 1872. Through cladistic analysis, using out-group and character correlation criteria, and a review of known Mesozoic fossil material, a hypothesis of phylogenetic relationships among extinct and extant Adephaga is developed, discussed, and related to geologic time. A semi-aquatic, rather than terrestrial, common ancestor is proposed for Adephaga. Amphizoids diverged from their sister-group, which includes all Hydradephaga except haliplids, in Triassic time. All extant amphizoid species had differentiated by late Pliocene time, in response to a series of vicariant events. Quaternary climatic and geologic events resulted in changes in geographical distributions of these species and structural, physiological, and behavioral adapta- tions of their members.