Georissus

Taxobox
name = "Georissus"
regnum = Animalia
phylum = Arthropoda
classis = Insecta
ordo = Coleoptera
subordo = Polyphaga
superfamilia = Hydrophiloidea
familia = Georissidae
familia_authority = Laporte, 1819
genus = "Georissus"
genus_authority = Latreille, 1809
subdivisionsee text

"Georissus", also called minute mud-loving beetles, are the only genus in the beetle family Georissidae (or Georyssidae). They are tiny insects living wet soil, often near water. Found on every continent except Antarctica.

Characteristics

Georissidae are small beetles (length 1-2 mm). They have broadly oval body with outline more or less interrupted between pronotum and elytra. Head and pronotum are with granulate sculpture, prosternum rudimentary, without intercoxal processes. Anterior coxae and trochanters are fused, basal ventrite is very large. [M.Hansen. Phylogeny and classification of the staphyliniform beetle families (Coleoptera). Biologiske Skrifter 48, Copenhagen, 1997]

ystematics and evolution

There are about 75 living species, including:
*"Georissus australis"
*"Georissus babai"
*"Georissus bipartitus"
*"Georissus caelatus"
*"Georissus californicus"
*"Georissus canalifer"
*"Georissus capitatus"
*"Georissus coelosternus"
*"Georissus costatus"
*"Georissus crenulatus"
*"Georissus formosanus"
*"Georissus fusicornis"
*"Georissus granulosus"
*"Georissus instabilis"
*"Georissus japonicus"
*"Georissus kingii"
*"Georissus kurosawai"
*"Georissus laesicollis"
*"Georissus minusculus"
*"Georissus occidentalis"
*"Georissus pusillus"
*"Georissus sakaii"
*"Georissus septemcostatus"
*"Georissus substriatus"
*"Georissus trifossulatus"The genus is divided into three subgenera ("Georissus", "Neogeorissus" and "Nipponogeorissus"). Formerly it was included within the family Hydrophilidae. Recent molecular data indicate, that they belong to a clade comprising the small groups of Hydrophiloidea - Epimetopidae, Hydrochidae, Helophoridae and Georissidae. [D.Bernhard et al., From terrestrial to aquatic habitats and back again — molecular insights into the evolution and phylogeny of Hydrophiloidea (Coleoptera) using multigene analyses. Zoologica Scripta 35 (6) , 597–606, 2006]

References