| The Nearctic species of Brychius Thomson 1859 (Coleoptera: Haliplidae) were revised by examining adult and larval specimens. There are three valid species in North America: Brychius hornii Crotch 1873, Brychius pacificus Carr 1928, and Brychius hungerfordi Spangler 1954. Brychius albertanus Carr 1928 is a junior subjective synonym of Brychius hornii Crotch 1873. Descriptions of adults and larvae (excluding B. pacificus), distribution data, and a key to adults are provided for all Nearctic species. From a reconstructed phylogeny of all species of Brychius, B. hornii + B. hungerfordi is the sister-group to the two European species, Brychius elevatus Panzer 1794 + Brychius glabratus Villa 1833. Brychius pacificus is the basal lineage. Because of limited dispersal capabilities, species of Brychius are thought to have arisen and diversified on Laurasia during the Jurassic Period. Brychius hornii and B. hungerfordi originated in the Tertiary Period before the advent of the Laramide orogeny, ca. 50 to 100 million years ago. (Abstract shortened by UMI.)... |
