Reclassification of Cybistrinae Sharp, 1880 in the Neotropical Region (Coleoptera, Adephaga, Dytiscidae), with description of new taxa Author Miller, Kelly B. https://orcid.org/0009-0004-1093-4066 Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM 87131 - 0001, USA kbmiller@unm.edu Author Michat, Mariano C. https://orcid.org/0000-0002-1962-7976 Instituto de Biodiversidad y Biologia Experimental y Aplicada, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina Author Ferreira Jr, Nelson https://orcid.org/0000-0002-5932-7695 Laboratorio de Entomologia, Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasi text ZooKeys 2024 2024-01-08 1188 125 168 http://dx.doi.org/10.3897/zookeys.1188.110081 journal article http://dx.doi.org/10.3897/zookeys.1188.110081 1313-2970-1188-125 997ADB92AFA7497982A2B81C00EF3AEA FD00287A8052513C815877D5359D01A1 Nilssondytes gen. nov. Figs 11 , 19 , 20 , 36-38 , 53 , 61 , 73 Type species. Nilssondytes diversus sp. nov., by current designation. Diagnosis. From other Cybistrinae this genus differs in having: (1) the metatibial spurs apically simple, (2) metacoxal lines clearly present, (3) the pronotum and elytron with broad, distinct lateral yellow bands along margins (Fig. 11 ), (4) males and females each with two metatarsal claws, the posterior much reduced in both sexes (Figs 19 , 20 ), (5) the prosternum and prosternal process relatively shallowly but distinctly sulcate, (6) the medial margins of the male sternite IX straight, not emarginate (Fig. 53 ), (7) no cluster or line of setae at the apicodorsal angle of the posterior surface of the mesotarsomeres, and (8) the ventral surface of the metatrochanter with an oblique, transverse groove. The single species in this genus (described below) is somewhat similar in size, shape and coloration to Metaxydytes laevigatus (Olivier) and may be present among series of that species in collections. Nilssondytes differ from M. laevigatus in several features (see above) including the presence of yellow lateral elytral margins (Fig. 11 ) which are absent in M. laevigatus . Larvae are unknown. Etymology. This genus is named Nilssondytes from the Latin dytes meaning "diver," and Nilsson , after the great diving beetle worker and excellent friend, Anders Nilsson, in honor of his inestimable contribution to the science of diving beetle biology. Phylogenetic relationships. The single species of Nilssondytes is part of the clade that includes species with an oblique metatrochanteric groove, but it has an unresolved position with respect to other genera (Figs 75 , 76 ). The presence of a reduced posterior metatarsal claw in both males and females (Figs 19 , 20 ) with the straight medial margins of the male abdominal sternite IX (Fig. 53 ) is a unique combination of features within Cybistrinae . Unique among this larger clade is also the sulcate prosternum and prosternal process which is somewhat similar to the Australian genera Spencerhydrus and Sternhydrus .