The phylogeny and evolutionary history of the whirligig beetle tribe Dineutini are inferred from the analysis of 56 morphological characters and DNA sequence data from the mitochondrial gene fragments COI, COII and 12S, and the nuclear gene fragments H3 and arginine kinase. Bayesian and maximum likelihood analyses were performed. A Bayesian tip-dating approach was taken to provide a time-calibrated phylogenetic tree incorporating fossil taxa. Seventy-one species of extant Gyrinidae were included in the analysis, as well as two fossil taxa, representing all dineutine genera and all proposed, nonmonotypic subgenera. The resulting trees strongly support the monophyly of the Dineutini and the genera Dineutus Macleay, 1825, Macrogyrus Regimbart, 1882, Porrorhynchus Laporte, 1835 and Enhydrus Laporte, 1835. The results do not support the distinction of Andogyrus Ochs, 1924 as a separate genus, nor do they support the majority of proposed subgenera. A new classification is presented here requiring the following taxonomic changes: Andogyrus stat. nov. is relegated to a subgenus of Macrogyrus; the following subgenera are synonymized with Macrogyrus s.s. sensu nov.: Australogyrus Ochs, 1949 syn. nov., Ballogyrus Ochs, 1949 syn. nov., Clarkogyrus Ochs, 1949 syn. nov., Megalogyrus Ochs, 1949 syn. nov., Orectomimus Ochs, 1930 syn. nov. and Tribologyrus Ochs, 1949 syn nov.; the subgenus Stephanogyrus Ochs, 1955 syn. nov. is synonymized with the subgenus Cyclomimus Ochs, 1929; the genus Dineutus now includes two subgenera: Cyclous Dejean, 1833 sensu nov. and the Dineutus s.s. subgenus sensu nov.; the following subgenera are synonymized with the subgenus Cyclous: Callistodineutus Ochs, 1926 syn. nov., Paracyclous Ochs, 1926 syn. nov., Protodineutus Ochs, 1926 syn. nov. and Spinosodineutes Hatch, 1926 syn. nov.; and the following subgenera are synonymized with the Dineutus s.s. subgenus: Rhombodineutus Ochs, 1926 syn. nov. and Merodineutus Ochs, 1955 syn nov. The subgenus Rhomborhynchus Ochs, 1926 incert. sed. is tentatively moved to the genus Dineutus, without phylogenetic placement. The analysis confirms Mesodineutese Ponomarenko, 1977 is a member of the Dineutini. Each genus and subgenus is reviewed in detail with (1) a morphological diagnosis, (2) its taxonomic circumscription, including the placement of species not included in the analysis, (3) known distribution and (4) relevant discussion. A new identification key to the extant genera and subgenera of the Dineutini is provided. Finally, a biogeographic analysis reconstructing ancestral ranges was conducted revealing the historical biogeography of the tribe. The historical biogeography of the /Dineutini was found to be dominated primarily by dispersal, and we report a new transpacific disjunct distribution for members of the genus Dineutus.
- aquatic beetle
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Animal Science and Zoology