Phylogeny of the supertribe Nebriitae (Coleoptera: Carabidae) based on analyses of DNA sequence data

<p>The phylogeny of the carabid beetle supertribe Nebriitae is inferred from analyses of DNA sequence data from eight gene fragments including one nuclear ribosomal gene (28S), four nuclear-protein coding genes (CAD, topoisomerase 1, PEPCK and <i>wingless</i>) and three mitochondrial gene fragments (16S + tRNA-Leu + ND1, COI ("barcode" region) and COI ("Pat/Jer" region)). Our taxon sample included 264 exemplars representing 241 species and subspecies (25% of the known nebriite fauna), 39 of 41 currently accepted genera and subgenera (all except <i>Notiokasis</i> and <i>Archileistobrius</i>), and eight outgroup taxa. Separate maximum likelihood (ML) analyses of individual genes, combined ML analyses of nuclear, nuclear protein-coding and mitochondrial genes, and combined ML and Bayesian analyses of the eight-gene-fragment matrix resulted in a well-resolved phylogeny of the supertribe, with most nodes in the tree strongly supported. Within Nebriitae, 167 internal nodes of the tree (out of the maximum possible 255) are supported by maximum-likelihood bootstrap values of 90% or more. Tribes Notiophilini, Opisthiini, Pelophilini, Nebriini are well supported as monophyletic but relationships among these are not well resolved. <i>Nippononebria</i> is a distinct genus more closely related to <i>Leistus</i> than <i>Nebria</i>. <i>Archastes, Oreonebria, Spelaeonebria, and Eurynebria</i>, previously treated as distinct genera by some authors,<i> </i>are all nested within a monophyletic genus <i>Nebria. </i>Within <i>Nebria</i>, four major clades are recognized: (1) the <i>Oreonebria</i> Series, including eight subgenera arrayed in two subgeneric complexes (the <i>Eonebria</i> and <i>Oreonebria</i> Complexes); (2) the <i>Nebriola</i> Series, including only subgenus <i>Nebriola</i>; (3) the <i>Nebria</i> Series, including ten subgenera arrayed in two subgeneric complexes, the <i>Boreonebria</i> and <i>Nebria </i>Complexes, with the latter further subdivided into three subgeneric subcomplexes (the <i>Nebria</i>, <i>Epinebriola</i> and <i>Eunebria</i> Subcomplexes)); and (4) the <i>Catonebria</i> Series, including seven subgenera arrayed in two subgeneric complexes (the <i>Reductonebria</i> and <i>Catonebria</i> Complexes). A strong concordance of biogeography with the inferred phylogeny is noted and some evident vicariance patterns are highlighted. A revised classification, mainly within the Nebriini, is proposed to reflect the inferred phylogeny. Three genus-group taxa (<i>Nippononebria</i>, <i>Vancouveria</i> and <i>Archastes</i>) are given revised status and seven are recognized as new synonymies (<i>Nebriorites</i> Jeannel, 1941 and <i>Marggia</i> Huber, 2014 = <i>Oreonebria</i> Daniel, 1903; <i>Pseudonebriola</i> Ledoux and Roux, 1989 = <i>Boreonebria</i> Jeannel, 1937; <i>Patrobonebria </i>Bänninger, 1923, <i>Paranebria </i>Jeannel, 1937 and <i>Barbonebriola</i> Huber and Schmidt, 2017 = <i>Epinebriola</i> Daniel and Daniel, 1904; and <i>Asionebria</i> Shilenkov, 1982 = <i>Psilonebria</i> Andrewes, 1923). Six new subgenera are proposed and described for newly recognized clades: <i>Parepinebriola</i> Kavanaugh subgen. nov. (type species: <i>Nebria delicata </i>Huber and Schmidt, 2017), <i>Insulanebria</i> Kavanaugh subgen. nov. (type species: <i>Nebria carbonaria</i> Eschscholtz, 1829), <i>Erwinebria</i> Kavanaugh subgen. nov. (type species <i>Nebria sahlbergii</i> Fischer von Waldheim, 1828), <i>Nivalonebria</i> Kavanaugh subgen. nov. (type species: <i>Nebria paradisi</i> Darlington, 1931), <i>Neaptenonebria</i> Kavanaugh subgen. nov. (type species: <i>Nebria ovipennis </i>LeConte, 1878) and <i>Palaptenonebria</i> Kavanaugh subgen. nov. (type species: <i>Nebria mellyi</i> Gebler, 1847). Future efforts to better understand relationships within the supertribe should aim to expand the taxon sampling of DNA sequence data, particulary within subgenera <i>Leistus</i> and <i>Evanoleist</i>us of genus <i>Leistus</i> and the <i>Nebria</i> Complex of genus <i>Nebria</i>.</p>