Georissus

Superregnum: Eukaryota
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Subphylum: Hexapoda
Classis: Insecta
Cladus: Dicondylia
Subclassis: Pterygota
Ordo: Coleoptera
Subordo: Polyphaga
Infraordo: Staphyliniformia
Superfamilia: Hydrophiloidea

Familia: Georissidae
Genus: Georissus
Subgenera:
G. (Georissus) – G. (Neogeorissus) – G. (Nipponogeorissus)
Overview of species (83)

G. amrishi – G. babai – G. bipartitus – G. caelatus – G. canalifer – G. chameleo – G. coelosternus – G. costatus – G. crenulatus – G. formosanus – G. fusicornis – G. granulosus – G. instabilis – G. japonicus – G. kurosawai – G. laesicollis – G. maritimus – G. minusculus – G. nemo – G. persicus – G. sakaii – G. septemcostatus – G. smetanai – G. substriatus – G. trifossulatus
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Name

Georissus Latreille, 1809

References

Fikáček, M.; Trávníček, D. 2009: Order Coleoptera, family Georissidae. Arthropod fauna of the UAE, 2: 145–148. PDF
Fikáček & Falamarzi 2010. Georissus persicus sp. nov. from Iran, with notes on the West-Palaearctic species of the G. laesicollis group (Coleoptera: Georissidae). Acta Entomologica Musei Nationalis Pragae 50(1): 107–116. Full article (PDF). Reference page.
Hebauer, F. 2004: Systematic and zoogeographical notes on the genus Georissus Latreille, 1809 (Coleoptera: Hydrophiloidea). Acta coleopterologica, 20(1): 3–6. PDF
Trávníček, D.; Fikáček, M. (in prep.): Revision of the Australian Georissus.

Links

BHL bibliography
Catalogue of Life: 2020 Annual Checklist
Georissus – Taxon details on Encyclopedia of Life (EOL).
Global Biodiversity Information Facility. 2019. GBIF Backbone Taxonomy. Checklist dataset. Taxon: Georissus.
ION
Minute mud-loving beetles of the genus Georissus (Georissidae) - atlas of beetles of Russia

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

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]

Species within this genus are known for their habit of psammophory (actively covering their elytra with sand or mud) which helps protect them against predators).[2]
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.[3]
References

M.Hansen. Phylogeny and classification of the staphyliniform beetle families (Coleoptera). Biologiske Skrifter 48, Copenhagen, 1997
Bameul, Franck (1989-01-01). "Description of the camouflage behaviour of a Coleoptera: The active disguise of Georissus crenulatus (Coleoptera Georissidae), and proposal of a new classification of disguises among invertebrates". 309: 351–356.
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