Necromys

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Necromys
Temporal range: Late Pliocene–Recent
Ratinho do Cerrado.jpg
Hairy-tailed bolo mouse (Necromys lasiurus)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Family: Cricetidae
Subfamily: Sigmodontinae
Tribe: Akodontini
Genus: Necromys
Ameghino, 1889
Type species
Necromys conifer [1]
Species
Synonyms
  • Bolomys Thomas 1916
  • CabreramysMassoia & Fornes 1967

Necromys is a genus of South American sigmodontine rodents allied to Akodon . [1] This genus has also been known as Cabreramys or more recently Bolomys, and the northern grass mouse (N. urichi) has recently been transferred from Akodon.

Contents

History

Most of the Brazilian members of the genus Necromys were first described in the second half of the nineteenth century, and the species from the Andes followed in the first decades of the twentieth century. [2] Small rodents in South America were studied by the British zoologist Oldfield Thomas, curator at the Natural History Museum, London who erected the genus Bolomys in 1916. [3]

Characteristics

Members of the genus Necromys are spread out over a wide area of Central and South America. Morphologically, members of the genus are difficult to distinguish from two other genera found in the same region, the grass mice Akodon and the cane mice Zygodontomys . [2] In 1987, the Argentine zoologist Osvaldo Reig listed the characteristics that distinguished the genus Bolomys from Akodon as; the braincase is broad and deep; the occipital region is short; the rostrum is fairly short; the rostrum tapers forwards when viewed from the side; the occiput is short and truncated; the zygomatic plate is broad, with the front edge straight or slightly concave; the upper incisors are orthodont or proodont; the molars are mesodont, broad and robust; the upper molars have transverse loops; and the lower molars have the lingual cusps slightly in front of the labial cusps. [3]

There is very little variation in the karyotype of Necromys, where 2n=34 is the rule, with N. lactens and N. lasiurus having diploid numbers of 2n=36. This is in great contrast to the explosively radiating Akodon which has diploid numbers ranging from 2n=14 to 2n=52. [4]

Species

Species listed in Necromys include:

Related Research Articles

<span class="mw-page-title-main">Sigmodontinae</span> Subfamily of rodents

The rodent subfamily Sigmodontinae includes New World rats and mice, with at least 376 species. Many authorities include the Neotominae and Tylomyinae as part of a larger definition of Sigmodontinae. When those genera are included, the species count numbers at least 508. Their distribution includes much of the New World, but the genera are predominantly South American, such as brucies. They invaded South America from Central America as part of the Great American Interchange near the end of the Miocene, about 5 million years ago. Sigmodontines proceeded to diversify explosively in the formerly isolated continent. They inhabit many of the same ecological niches that the Murinae occupy in the Old World.

<span class="mw-page-title-main">Akodontini</span> Tribe of rodents

Akodontini is the second most speciose rodent tribe of the subfamily Sigmodontinae. It includes at least 106 living species in 19 genera and is distributed mainly in the southern half of South America, with only two genera extending into Guyana (Podoxymys) and Venezuela (Necromys). It also includes genera previously placed in tribe Scapteromyini. The following genera are now generally recognized:

<i>Akodon</i> Genus of rodents

Akodon is a genus consisting of South American grass mice. They mostly occur south of the Amazon Basin and along the Andes north to Venezuela, but are absent from much of the basin itself, the far south of the continent, and the lowlands west of the Andes. Akodon is one of the most species-rich genera of Neotropical rodents. Species of Akodon are known to inhabit a variety of habitats from tropical and tropical moist forests to altiplano and desert. Fossils are known from the late Pliocene onwards.

The cursor grass mouse, or cursorial akodont, is a sigmodontine rodent from South America.

<span class="mw-page-title-main">Hairy-tailed bolo mouse</span> Species of rodent

The hairy-tailed bolo mouse or hairy-tailed akodont is a South American rodent species of the family Cricetidae. It is found in Argentina, Bolivia, Brazil, and Paraguay.

The hairy-eared cerrado mouse or hairy-eared akodont, is a rodent species from South America. It is found in the cerrado grassland of Brazil.

<i>Akodon spegazzinii</i> Rodent in the family Cricetidae found in northwestern Argentina

Akodon spegazzinii, also known as Spegazzini's akodont or Spegazzini's grass mouse, is a rodent in the genus Akodon found in northwestern Argentina. It occurs in grassland and forest at 400 to 3,500 m above sea level. After the species was first named in 1897, several other names were given to various populations now included in A. spegazzinii. They are now all recognized as part of a single, widespread and variable species. Akodon spegazzinii is related to Akodon boliviensis and other members of the A. boliviensis species group. It reproduces year-round. Because it is widely distributed and common, Akodon spegazzinii is listed as "least concern" on the IUCN Red List.

The pleasant bolo mouse, or pleasant akodont, is a species of rodent in the family Cricetidae. It is found on grassland at high altitudes in Bolivia and Peru.

The spotted bolo mouse or Ecuadorian akodont is a species of rodent in the family Cricetidae. It is known from Ecuador and may also occur in Colombia. Little is known of its status and range.

<i>Akodon caenosus</i> Species of rodent

Akodon caenosus is a rodent in the genus Akodon found in northwestern Argentina and south-central Bolivia. Since its description in 1918, it has been alternatively classified as a separate species or a subspecies of Akodon lutescens. The species Akodon aliquantulus, described from some very small Argentine specimens in 1999, is now recognized as a synonym of A. caenosus.

The Paraguayan bolo mouse or Paraguayan akodont is a species of rodent in the family Cricetidae. According to the IUCN, it is present in Bolivia, Paraguay, and Peru, and possibly also in Argentina and Brazil. It is found at elevations from 300 to 2,030 m in a variety of habitats, including cerrado, chaco, and heath pampas.

<span class="mw-page-title-main">Cerrado climbing mouse</span> Species of rodent

The cerrado climbing mouse or long-tailed rhipidomys is an arboreal rodent species in the family Cricetidae from South America. It is found in primary or secondary forests of the cerrado and caatinga in central and eastern Brazil, and has also been seen in the Atlantic Forest. Its karyotype is 2n = 44, FN = 48-52. They are nocturnal animals and can be found in both tree canopies and on the ground.

<i>Thomasomys ucucha</i> Species of rodent from Ecuador

Thomasomys ucucha, also known as the ucucha thomasomys, is a rodent in the genus Thomasomys of the family Cricetidae. It is known only from high altitude forest and grassland habitats in the Cordillera Oriental of Ecuador. Seven other species of Thomasomys live in the same areas. First collected in 1903, T. ucucha was formally described as a new species in 2003 and most closely resembles T. hylophilus, which occurs further to the north. The species is listed as "vulnerable" in the IUCN Red List as a result of habitat destruction.

<i>Juliomys anoblepas</i> Species of rodent

Juliomys anoblepas is a rodent in the genus Juliomys of the subfamily Sigmodontinae known from a single broken skull. The specimen was collected by Peter Wilhelm Lund in the caves of Lagoa Santa, Minas Gerais, Brazil, in the first half of the 19th century and described by Herluf Winge in 1888 as Calomys anoblepas. The species remained unstudied and its affinities unclear until 2011, when it was recognized as a member of the genus Juliomys, which includes three other species from southern Brazil and nearby Argentina and Paraguay. J. anoblepas is probably a separate extinct species of the genus, which is no longer found at Lagoa Santa.

References

  1. 1 2 Musser, G.G.; Carleton, M.D. (2005). "Superfamily Muroidea". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 1130–1131. ISBN   978-0-8018-8221-0. OCLC   62265494.
  2. 1 2 Patton, James L. (2015). Mammals of South America, Volume 2: Rodents. University of Chicago Press. pp. 232–235. ISBN   978-0-226-16957-6.
  3. 1 2 Eisenberg, John F.; Redford, Kent H. (1992). Mammals of the Neotropics, Volume 2: The Southern Cone: Chile, Argentina, Uruguay, Paraguay. University of Chicago Press. p. 316. ISBN   978-0-226-70682-5.
  4. ↑ Fontdevila, Antonio (2012). Evolutionary Biology of Transient Unstable Populations. Springer Science & Business Media. pp. 270–271. ISBN   978-3-642-74525-6.
  5. ↑ Jayat, J.P.; et al. (September 2016). "A new species of the rodent genus Necromys Ameghino (Cricetidae: Sigmodontinae: Akodontini) from the Chaco Serrano grasslands of northwestern Argentina". Journal of Mammalogy. 97 (5): 1321–1335. doi:10.1093/jmammal/gyw103. hdl: 11336/46327 .
  6. ↑ Farola Monte Hermoso FI Facies at Fossilworks.org
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