''Oxysternon'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea. 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 A pen name, also called a ''nom de plume'' or a literary double, is a pseudonym (or, in some cases, a variant form of a real name) adopted by an author and printed on the title page or by-line of their works in place of their real name. A pen na ...

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 In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

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, 1767) pag
552
/ref> * '' Oxysternon lautum'' (Macleay, 1819) * '' Oxysternon macleayi'' (Nevinson, 1892) * '' Oxysternon palaemon'' Laporte, 1840 * ''

Oxysternon pteroderum ''Oxysternon'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea. It can be distinguished from all other phanaeines and scarabaeine dung beetles by a long, spiniform extension of the anterior angle of the metasternum ...

'' Nevinson, 1892 * '' Oxysternon silenus'' Laporte, 1840 * '' Oxysternon spiniferum'' Laporte, 1840 * ''

Oxysternon striatopunctatum ''Oxysternon'' is a genus of Scarabaeidae or scarab beetles in the superfamily Scarabaeoidea. It can be distinguished from all other phanaeines and scarabaeine dung beetles by a long, spiniform extension of the anterior angle of the metasternum. ...

'' Olsoufieff, 1924

Distribution

''Oxysternon'' is a neotropical 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 southe ...

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 technology c ...

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 region and the

Atlantic coastal forest The Atlantic Forest ( pt, Mata Atlântica) is a South American forest that extends along the Atlantic coast of Brazil from Rio Grande do Norte state in the northeast to Rio Grande do Sul state in the south and inland as far as Paraguay and the ...

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