''Oxysternon'' is a genus of

Scarabaeidae The family Scarabaeidae, as currently defined, consists of over 30,000 species of beetles worldwide; they are often called scarabs or scarab beetles. The classification of this family has undergone significant change in recent years. Several sub ...

or scarab beetles in the superfamily

Scarabaeoidea Scarabaeoidea is a superfamily of beetles, the only subgroup of the infraorder Scarabaeiformia. Around 35,000 species are placed in this superfamily and some 200 new species are described each year. Its constituent families are also undergoing r ...

. It can be distinguished from all other phanaeines and scarabaeine dung beetles by a long, spiniform extension of the anterior angle of the metasternum. Most taxa vary in color and color pattern, and are more commonly found in tones of green, often infused with yellow or coppery highlights. All species appear very smooth or glassy smooth to the unaided eye.

Taxonomy and nomenclature

The genus ''Sternaspis'' was proposed first by Hope in 1837, but the name was preoccupied and thus invalid. Laporte, writing under the pen name of Le Compte de Castelnau, proposed the genus Oxysternon to include several species of Phaneus-like species. ''O. festivum'' was later designated as the type species., pag
82
/ref>

Phylogeny and evolution

The genus is monophyletic and its sister group is the genus Phanaeus. Two subgenera and two further species groups are recognized by some authors. It has been suggested that the current distribution of the species reflect vicariance events following climatic fluctuations in the Amazon.

Diversity

There are currently 11 species in the genus ''Oxysternon''. * '' Oxysternon conspicillatum'' Weber, 1801 * '' Oxysternon durantoni'' Arnaud, 1984 * '' Oxysternon ebeninum'' (Nevinson, 1890) * '' Oxysternon festivum'' (

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

, 1767) pag
552
/ref> * '' Oxysternon lautum'' (Macleay, 1819) * '' Oxysternon macleayi'' (Nevinson, 1892) * '' Oxysternon palaemon'' Laporte, 1840 * '' Oxysternon pteroderum'' Nevinson, 1892 * '' Oxysternon silenus'' Laporte, 1840 * '' Oxysternon spiniferum'' Laporte, 1840 * '' Oxysternon striatopunctatum'' Olsoufieff, 1924

Distribution

''Oxysternon'' is a

neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bioge ...

genus occurring north of the

Tropic of Capricorn The Tropic of Capricorn (or the Southern Tropic) is the circle of latitude that contains the subsolar point at the December (or southern) solstice. It is thus the southernmost latitude where the Sun can be seen directly overhead. It also reac ...

and east of the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

. Only two, widespread species are found in the northwest of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

and up to the southern portion of

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

. Most ''Oxysternon'' species have restricted distributions within the

Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technolog ...

basin, the

Guiana Shield The Guiana Shield (french: Plateau des Guyanes, Bouclier guyanais; nl, Hoogland van Guyana, Guianaschild; pt, Planalto das Guianas, Escudo das Guianas; es, Escudo guayanés) is one of the three cratons of the South American Plate. It is a ...

, the

Cerrado The ''Cerrado'' (, ) is a vast ecoregion of tropical savanna in eastern Brazil, particularly in the states of Goiás, Mato Grosso do Sul, Mato Grosso, Tocantins, Minas Gerais, and the Federal District. The core areas of the Cerrado biome are the ...

region and the Atlantic coastal forest of

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

Ecology

''Oxysternon palaemon'' is a common beetle in the cerrado formations of Brazil and adjacent areas of Bolivia and Paraguay. All other species inhabit supermoist to mesic forest habitats with different degrees of tolerance to fragmentation and

forest degradation Forest degradation is a process in which the biological wealth of a forest area is permanently diminished by some factor or by a combination of factors. "This does not involve a reduction of the forest area, but rather a quality decrease in its c ...

. The behavior of ''Oxysternon'' species has not been studied in detail. All species seem to be coprophagous or copro-necrophagous, although fruit pulp is sometimes used as an adult food resource.

References

{{Taxonbar, from=Q3359154 Scarabaeidae