<documentID-CLB-Dataset="284562"ID-DOI="http://dx.doi.org/10.3897/zookeys.1188.110081"ID-GBIF-Dataset="2d7e899e-e8ef-43d0-bc1e-a1472bb4e30d"ID-PMC="PMC10790577"ID-Pensoft-Pub="1313-2970-1188-125"ID-Pensoft-UUID="FD00287A8052513C815877D5359D01A1"ID-PubMed="38230379"ID-ZooBank="997ADB92AFA7497982A2B81C00EF3AEA"ModsDocID="1313-2970-1188-125"checkinTime="1704768536908"checkinUser="pensoft"docAuthor="Miller, Kelly B., Michat, Mariano C. & Ferreira Jr, Nelson"docDate="2024"docId="20663EA9E0075488B9BA7699E63FF9FC"docLanguage="en"docName="ZooKeys 1188: 125-168"docOrigin="ZooKeys 1188"docPubDate="2024-01-08"docSource="http://dx.doi.org/10.3897/zookeys.1188.110081"docTitle="Nilssondytes Miller & Michat & Ferreira Jr 2024, gen. nov."docType="treatment"docUuid="DF8AFDB0-B369-4936-B231-84B942B58258"docUuidSource="ZooBank"docVersion="4"id="FD00287A8052513C815877D5359D01A1"lastPageNumber="125"masterDocId="FD00287A8052513C815877D5359D01A1"masterDocTitle="Reclassification of Cybistrinae Sharp, 1880 in the Neotropical Region (Coleoptera, Adephaga, Dytiscidae), with description of new taxa"masterLastPageNumber="168"masterPageNumber="125"pageNumber="125"updateTime="1732489170790"updateUser="ExternalLinkService">
<mods:titleid="85841E81EA80FC055CE3EF3BF7CD22BD">Reclassification of Cybistrinae Sharp, 1880 in the Neotropical Region (Coleoptera, Adephaga, Dytiscidae), with description of new taxa</mods:title>
<mods:affiliationid="129DDFB6CA1054B3516AE049449A80F5">Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM 87131 - 0001, USA</mods:affiliation>
<mods:affiliationid="8D4D9643A3F0932020FC49EEBF64C942">Instituto de Biodiversidad y Biologia Experimental y Aplicada, CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina</mods:affiliation>
<mods:affiliationid="0F41E33C2DFC4D484CEE40F413F9CE21">Laboratorio de Entomologia, Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasi</mods:affiliation>
<taxonomicNameid="5EE45775C8DC2104C5A12AC82ABB517E"LSID="https://zoobank.org/DF8AFDB0-B369-4936-B231-84B942B58258"authority="Miller & Michat & Ferreira Jr, 2024"authorityName="Miller & Michat & Ferreira Jr"authorityYear="2024"class="Insecta"family="Dytiscidae"genus="Nilssondytes"higherTaxonomySource="CoL"kingdom="Animalia"lsidName="Nilssondytes"order="Coleoptera"pageId="0"pageNumber="125"phylum="Arthropoda"rank="genus"status="gen. nov.">Nilssondytes</taxonomicName>
<figureCitationid="D09C0CDA9ECEFD17AF36E78E8B2E76B6"captionStart="Figures 9–14"captionStartId="F2"captionText="Figures 9 - 14. Neotropical Cybistrinae species, habitus 9 Cybister festae 10 Cybister puncticollis 11 Nilssondytes diversus 12 Megadytes parvus 13 Megadytes latus 14 species " IR 57 " (Ribera et al. 2008). Scale bar: 10.0 mm."figureDoi="10.3897/zookeys.1188.110081.figures9-14"httpUri="https://binary.pensoft.net/fig/963584"pageId="0"pageNumber="125">Figs 11</figureCitation>
<figureCitationid="17551C3424C33E1FC54B6F98A28FC71D"captionStart="Figures 15–29"captionStartId="F3"captionText="Figures 15 - 29. Neotropical Cybistrinae species, metatarsal claws and tarsomere VI of males and females 15, 16 Cybister festae 17, 18 Cybister puncticollis 19, 20 Nilssondytes diversus 21, 22 Megadytes latus 23, 24 Megadytes parvus 25 species " IR 57 " (Ribera et al. 2008) 26, 27 Paramegadytes glaucus 28, 29 Metaxydytes fraternus. Scale bars: 1.0 mm."figureDoi="10.3897/zookeys.1188.110081.figures15-29"httpUri="https://binary.pensoft.net/fig/963585"pageId="0"pageNumber="125">, 19</figureCitation>
<figureCitationid="453DA61E78A0A20C4EB76850BF63D652"captionStart="Figures 15–29"captionStartId="F3"captionText="Figures 15 - 29. Neotropical Cybistrinae species, metatarsal claws and tarsomere VI of males and females 15, 16 Cybister festae 17, 18 Cybister puncticollis 19, 20 Nilssondytes diversus 21, 22 Megadytes latus 23, 24 Megadytes parvus 25 species " IR 57 " (Ribera et al. 2008) 26, 27 Paramegadytes glaucus 28, 29 Metaxydytes fraternus. Scale bars: 1.0 mm."figureDoi="10.3897/zookeys.1188.110081.figures15-29"httpUri="https://binary.pensoft.net/fig/963585"pageId="0"pageNumber="125">, 20</figureCitation>
<figureCitationid="213CE03333E8BAF4D6C6E399529AD160"captionStart="Figures 30–50"captionStartId="F4"captionText="Figures 30 - 50. Neotropical Cybistrinae species, male genitalia 30 - 32 Cybister festae: 30 median lobe, right lateral aspect 31 median lobe, ventral aspect 32 right lateral lobe, right lateral aspect 33 - 35 Cybister puncticollis: 33 median lobe, right lateral aspect 34 median lobe, ventral aspect 35 right lateral lobe, right lateral aspect 36 - 38 Nilssondytes diversus: 36 median lobe, right lateral aspect 37 median lobe, ventral aspect 38 right lateral lobe, right lateral aspect 39 - 43 Megadytes parvus: 39 median lobe, right lateral aspect 40 median lobe, ventral aspect 41 right lateral lobe, right lateral aspect 42 apex of median lobe, right lateral aspect 43 apex of median lobe, ventral aspect 44 - 47 Megadytes latus: 44 median lobe, right lateral aspect 45 median lobe, ventral aspect 46 right lateral lobe, right lateral aspect 47 apex of median lobe, ventral aspect 48 - 50 species " IR 57 " (Ribera et al. 2008): 48 median lobe, right lateral aspect 49 median lobe, ventral aspect 50 right lateral lobe, right lateral aspect."figureDoi="10.3897/zookeys.1188.110081.figures30-50"httpUri="https://binary.pensoft.net/fig/963586"pageId="0"pageNumber="125">, 36-38</figureCitation>
<taxonomicNameid="E33525A426E8A7D3FC4D2A8572569508"authorityName="Miller & Michat & Ferreira Jr"authorityYear="2024"class="Insecta"family="Dytiscidae"genus="Nilssondytes"higherTaxonomySource="CoL"kingdom="Animalia"lsidName="Nilssondytes diversus"order="Coleoptera"pageId="0"pageNumber="125"phylum="Arthropoda"rank="species"species="diversus">
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.
<figureCitationid="6B527B17B73289FF23AE789D2B17B550"captionStart="Figures 9–14"captionStartId="F2"captionText="Figures 9 - 14. Neotropical Cybistrinae species, habitus 9 Cybister festae 10 Cybister puncticollis 11 Nilssondytes diversus 12 Megadytes parvus 13 Megadytes latus 14 species " IR 57 " (Ribera et al. 2008). Scale bar: 10.0 mm."figureDoi="10.3897/zookeys.1188.110081.figures9-14"httpUri="https://binary.pensoft.net/fig/963584"pageId="0"pageNumber="125">11</figureCitation>
), (4) males and females each with two metatarsal claws, the posterior much reduced in both sexes (Figs
<figureCitationid="650084DC53234AA06C31B53CEE3B1B55"captionStart="Figures 15–29"captionStartId="F3"captionText="Figures 15 - 29. Neotropical Cybistrinae species, metatarsal claws and tarsomere VI of males and females 15, 16 Cybister festae 17, 18 Cybister puncticollis 19, 20 Nilssondytes diversus 21, 22 Megadytes latus 23, 24 Megadytes parvus 25 species " IR 57 " (Ribera et al. 2008) 26, 27 Paramegadytes glaucus 28, 29 Metaxydytes fraternus. Scale bars: 1.0 mm."figureDoi="10.3897/zookeys.1188.110081.figures15-29"httpUri="https://binary.pensoft.net/fig/963585"pageId="0"pageNumber="125">19</figureCitation>
,
<figureCitationid="2C3D4BF4863BE806CAB1CD4E3024BF39"captionStart="Figures 15–29"captionStartId="F3"captionText="Figures 15 - 29. Neotropical Cybistrinae species, metatarsal claws and tarsomere VI of males and females 15, 16 Cybister festae 17, 18 Cybister puncticollis 19, 20 Nilssondytes diversus 21, 22 Megadytes latus 23, 24 Megadytes parvus 25 species " IR 57 " (Ribera et al. 2008) 26, 27 Paramegadytes glaucus 28, 29 Metaxydytes fraternus. Scale bars: 1.0 mm."figureDoi="10.3897/zookeys.1188.110081.figures15-29"httpUri="https://binary.pensoft.net/fig/963585"pageId="0"pageNumber="125">20</figureCitation>
), (5) the prosternum and prosternal process relatively shallowly but distinctly sulcate, (6) the medial margins of the male sternite IX straight, not emarginate (Fig.
), (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
<taxonomicNameid="9F1AB643F684FCC6D331B3AC43AF9614"authorityName="Miller & Michat & Ferreira Jr"authorityYear="2024"class="Insecta"family="Dytiscidae"genus="Nilssondytes"higherTaxonomySource="CoL"kingdom="Animalia"lsidName="Nilssondytes"order="Coleoptera"pageId="0"pageNumber="125"phylum="Arthropoda"rank="genus">
<taxonomicNameid="64E56518C3145C3C24BA8B677ABEFF63"authorityName="Miller & Michat & Ferreira Jr"authorityYear="2024"class="Insecta"family="Dytiscidae"genus="Nilssondytes"higherTaxonomySource="CoL"kingdom="Animalia"lsidName="Nilssondytes"order="Coleoptera"pageId="0"pageNumber="125"phylum="Arthropoda"rank="genus">
, after the great diving beetle worker and excellent friend, Anders Nilsson, in honor of his inestimable contribution to the science of diving beetle biology.
<taxonomicNameid="235359D2C9179F36AADDD572FF78D21E"authorityName="Miller & Michat & Ferreira Jr"authorityYear="2024"class="Insecta"family="Dytiscidae"genus="Nilssondytes"higherTaxonomySource="CoL"kingdom="Animalia"lsidName="Nilssondytes"order="Coleoptera"pageId="0"pageNumber="125"phylum="Arthropoda"rank="genus">
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
<figureCitationid="A99C762B15E24845DF82740D4FD62DBB"captionStart="Figure 75"captionStartId="F12"captionText="Figure 75. One of seven cladograms derived from parsimony analysis of 57 morphological characters from Cybistrinae and other Dytiscidae (len = 105, CI = 68, RI = 92) with characters mapped using ' fast' optimization in WinClada. Black hash marks indicate unambiguous changes, white hash marks indicate homoplasious changes or reversals. Numbers above hash marks are character numbers, those below hash marks are derived state numbers."figureDoi="10.3897/zookeys.1188.110081.figure75"httpUri="https://binary.pensoft.net/fig/963593"pageId="0"pageNumber="125">75</figureCitation>
,
<figureCitationid="0E20455F9E9913F45FCA76D446D5EDAA"captionStart="Figure 76"captionStartId="F13"captionText="Figure 76. Consensus cladogram of seven equally parsimonious cladograms from parsimony analysis of 57 morphological characters from Cybistrinae and other Dytiscidae morphology."figureDoi="10.3897/zookeys.1188.110081.figure76"httpUri="https://binary.pensoft.net/fig/963594"pageId="0"pageNumber="125">76</figureCitation>
). The presence of a reduced posterior metatarsal claw in both males and females (Figs
<figureCitationid="76CA96AB9A7330AA44276DF90E4129C2"captionStart="Figures 15–29"captionStartId="F3"captionText="Figures 15 - 29. Neotropical Cybistrinae species, metatarsal claws and tarsomere VI of males and females 15, 16 Cybister festae 17, 18 Cybister puncticollis 19, 20 Nilssondytes diversus 21, 22 Megadytes latus 23, 24 Megadytes parvus 25 species " IR 57 " (Ribera et al. 2008) 26, 27 Paramegadytes glaucus 28, 29 Metaxydytes fraternus. Scale bars: 1.0 mm."figureDoi="10.3897/zookeys.1188.110081.figures15-29"httpUri="https://binary.pensoft.net/fig/963585"pageId="0"pageNumber="125">19</figureCitation>
,
<figureCitationid="5081E0CCC0099AF1DF765133620E2E54"captionStart="Figures 15–29"captionStartId="F3"captionText="Figures 15 - 29. Neotropical Cybistrinae species, metatarsal claws and tarsomere VI of males and females 15, 16 Cybister festae 17, 18 Cybister puncticollis 19, 20 Nilssondytes diversus 21, 22 Megadytes latus 23, 24 Megadytes parvus 25 species " IR 57 " (Ribera et al. 2008) 26, 27 Paramegadytes glaucus 28, 29 Metaxydytes fraternus. Scale bars: 1.0 mm."figureDoi="10.3897/zookeys.1188.110081.figures15-29"httpUri="https://binary.pensoft.net/fig/963585"pageId="0"pageNumber="125">20</figureCitation>
) with the straight medial margins of the male abdominal sternite IX (Fig.
