Georissus

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Georissus
Georissus.laesicollis.-.calwer.16.25.jpg
G. laesicollis
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, is the only genus in the beetle family Georissidae (or Georyssidae). They are tiny insects living in wet soil, often near water. Found on every continent except Antarctica.

Characteristics[edit]

Georissidae are small beetles (length 1–2 mm). They have a broadly oval body whose outline is more or less interrupted between the pronotum and the elytra. The head and pronotum are granulate, the prosternum is rudimentary, without intercoxal processes. The anterior coxae and trochanters are fused. The basal ventrite is very large.[1]

Systematics and evolution[edit]

There are about 75 living species, including:

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]

References[edit]

  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