Georissus

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Georissus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Superfamily: Hydrophiloidea
Family: Georissidae
Laporte, 1819
Genus: Georissus
Latreille, 1809

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.

[edit] 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. worldwide[1]

[edit] Systematics 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.[2]

[edit] References

  1. ^ M.Hansen. Phylogeny and classification of the staphyliniform beetle families (Coleoptera). Biologiske Skrifter 48, Copenhagen, 1997
  2. ^ 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