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.
A cotton rat is any member of the rodent genus Sigmodon. Their name derives from their damaging effects on cotton as well as other plantation crops, such as sugarcane, corn, peanut and rice. Cotton rats have small ears and dark coats, and are found in North and South America. Members of this genus are distributed in the Southwestern United States, Mexico, Central America, and South American countries of: Venezuela, Ecuador, Colombia, Peru, Brazil, Guyana, and Suriname. Many of the species are found in Mexico.
Oryzomys is a genus of semiaquatic rodents in the tribe Oryzomyini living in southern North America and far northern South America. It includes eight species, two of which—the marsh rice rat (O. palustris) of the United States and O. couesi of Mexico and Central America—are widespread; the six others have more restricted distributions. The species have had eventful taxonomic histories, and most species were at one time included in the marsh rice rat; additional species may be recognized in the future. The name Oryzomys was established in 1857 by Spencer Fullerton Baird for the marsh rice rat and was soon applied to over a hundred species of American rodents. Subsequently, the genus gradually became more narrowly defined until its current contents were established in 2006, when ten new genera were established for species previously placed in Oryzomys.
Oligoryzomys nigripes, also known as the black-footed colilargo or the black-footed pygmy rice rat, is a rodent in the genus Oligoryzomys of family Cricetidae. Oligoryzomys nigripes is a species that has been further divided into different sister taxa throughout history. It is found in different countries in South America. It is a large species with long ears, dark yellow to dark brown upperparts, sharply delimited from the whitish underparts, and often a pink girdle on the chest. This species of rat spends much of its life among the trees. The karyotype is 2n = 62, FNa = 78–82.
The hispid cotton rat is a rodent species long thought to occur in parts of South America, Central America, and southern North America. However, recent taxonomic revisions, based on mitochondrial DNA sequence data, have split this widely distributed species into three separate species. The distribution of S. hispidus ranges from Arizona in the west to Virginia to the east and from the Platte River in Nebraska in the north to, likely, the Rio Grande in the south, where it meets the northern edge of the distribution of S. toltecus. Adult size is total length 202–340 mm (8.0–13.4 in); tail 87–122 mm (3.4–4.8 in), frequently broken or stubbed; hind foot 29–35 mm (1.1–1.4 in); ear 16–20 mm (0.63–0.79 in); mass 50–250 g (1.8–8.8 oz). They have been used as laboratory animals.
The southern pygmy mouse is a species of rodent in the family Cricetidae. It is found in El Salvador, Guatemala, Honduras, Mexico, and Nicaragua.
The Tres Marías island mouse or Tres Marías deer mouse is a species of rodent in the family Cricetidae. It is found only on the Islas Marías off the west coast of Mexico. When last assessed, it was common on María Cleofás Island, but rare or absent on the other, more disturbed, islands.
The tawny deer mouse or marsh mouse is a species of rodent in the family Cricetidae. It is found only in Mexico.
The Arizona cotton rat or Colorado River cotton rat is a species of rodent in the family Cricetidae. It is found in Mexico and the United States.
The tawny-bellied cotton rat is a species of rodent in the family Cricetidae. It is found in Mexico and in the US states of Arizona and New Mexico.
The yellow-nosed cotton rat is a species of rodent in the family Cricetidae. It is native to Mexico and to the states of Arizona, New Mexico, and Texas in the United States, where it inhabits mountain grassland, scrub, and pinyon-juniper woodland. It is common over much of its wide range and the IUCN considers it to be of "least concern".
The Toltec cotton rat is a rodent species in the family Cricetidae. It is found in eastern Mexico from the Rio Grande to the Yucatán Peninsula, as well as in Belize and northern Guatemala. It prefers moist grassland habitat. While long thought to be a subspecies of S. hispidus, recent taxonomic revisions, based on mitochondrial DNA sequence data, have split the extensive former species range into three separate species. Carroll et al. (2004) indicate that the southern edge of the S. hispidus distribution is likely near the Rio Grande where it meets the northern distribution of S. toltecus. The range of S. toltecus extends from northern Mexico south into Chiapas where it occurs in sympatry with S. hirsutus . Rats from this species group have been used as laboratory animals.
The Miahuatlán cotton rat was formerly considered a rodent species in the family Cricetidae. It is found only on the Pacific slope of the Sierra de Miahuatlán in the Mexican state of Oaxaca, where it lives in deciduous tropical forest. The IUCN currently considers it to be conspecific with Sigmodon alleni.
Mastophorus muris is a parasitic nematode in the genus Mastophorus. It infects animals such as the marsh rice rat, hispid cotton rat, and singing vole.
Prolistrophorus bakeri is a parasitic mite in the genus Prolistrophorus. Together with the Argentine P. hirstianus, it forms the subgenus Beprolistrophorus. P. bakeri has been found on the hispid cotton rat, marsh rice rat, and cotton mouse in Georgia, South Carolina, Texas, and Florida and on Oryzomys couesi in Colima. It was formerly placed in the genus Listrophorus.
Playa de Oro virus (OROV) is a probable species of orthohantavirus found in the rodents Oryzomys couesi and Sigmodon mascotensis in the Mexican state of Colima. The former is thought to be the main host. The sequences of parts of the virus's RNA-based genome have been determined; they differ by 7–10% in amino acid composition and 22–24% in nucleotide composition from closely related viruses.
Soriano's yellow-shouldered bat, is an extant species of leaf-nosed bat indigenous to Bolivia and Venezuela, although its precise distribution is uncertain. Following the postulation of the species in 2005, S. sorianoi requires contemporary information relating its distribution, environment, and population, along with formal a comparison with S. erythromos and S. bogotensis. Without sufficient data, the International Union for Conservation of Nature (IUCN) presently considers the taxonomy for S. sorianoi as incomplete.
El Moro Canyon orthohantavirus is a single-stranded, negative sense RNA virus of the genus Orthohantavirus. It is a causative agent of Hantavirus pulmonary syndrome.
Montano orthohantavirus, also called Montano virus (MTNV) is a single-stranded, enveloped, negative sense RNA species of hantavirus. It was first isolated in Mexican wild rodents located in Morelos and Guerrero, Mexico.
Eumops ferox, the fierce bonneted bat or the chestnut mastiff bat, is a species of free-tailed bat found in the Caribbean and Mexico. Until recently, it was synonymous with Wagner's bonneted bat.
