This article needs additional citations for verification .(December 2009) |
Marmosops | |
---|---|
Marmosops incanus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Infraclass: | Marsupialia |
Order: | Didelphimorphia |
Family: | Didelphidae |
Subfamily: | Didelphinae |
Tribe: | Thylamyini |
Genus: | Marmosops Matschie 1916 |
Type species | |
Didelphis incana Lund 1840 | |
Species | |
See text |
Marmosops is a genus of Neotropical opossums of the family Didelphidae. The genus was originally treated as a subgenus from the genus Marmosa rather than having their own classification. This was changed in 1989 by Gardner and Crieghton, who officially separated the group and made them their own genus. The mix-up between to genera Marmosa and Marmosops was common due to the similar appearances including size and other external features. However, the two groups differ significantly in their integument and in the arrangement of their skull and dentition. [1] The dentition is similar in morphology between the two groups, with the exception of the deciduous lower third premolar varying from one genus to the next. The similarity between the two continues to cause the genus Marmosops to be frequently misidentified due to the lack of knowledge regarding the species along with the overlooked traits that help separate them from other opossums. [1] The Marmosops are also commonly confused with the genus Gracilinanus , but this is quickly ruled out by a large number of differing characteristics. [1] These differences include the arrangement of their digits, caudal (anatomical term) scales, and the central hair on the scales changing from a three hairs per follicle to many more. This causes the hair of the Gracilinanus to be thicker and has also found to be heavily pigmented. [1] The last group commonly confused with Marmosops is known as the genus Thylamys . These animals have a contrasting dorsal body pelage and the taxa are actually quite different. [1]
Cladogram of living Marmosops [2] [3] |
The genus Marmosops includes the following species: [4]
Some species are recognized by the Mammal Species of the World, but not by the American Society of Mammalogists:
The Marmosops tend to be nocturnal, small marsupials and have been found to live on the ground. Many females of the M. paulensis species are known to be extremely territorial with a strong defense of their food, especially while in the presence of their young. [12] The genus Marmosops is frequently misidentified and lumped into groups containing other species. [13] As of today, Marmosops are currently recognized as a distinct taxon with 36 taxa: 14 valid species and 22 subspecies. [1] The species within the genus differ slightly, but not enough to be classified as separate genera. Some of the species are also nicknamed by appearance, with the M. paulensis known as the slender opossum, the M. noctivagus recognized as the largest species and the M. bishopi the smallest of the genus. [14]
The main habitat for the Marmosops is found between the Neotropical humid forests ranging from Panama to the South of Brazil and sometimes in Bolivia as well. [13] The Marmosops prefer to live on the grounds of forests, staying away from high branches of trees. They often hide in the dense understory with high plant coverage surrounding them. They are highly influenced by rain and predation, with migration occurring more often during certain seasons. [15] The genus is never found to live up in a canopy (biology) or in the trees, but instead typically prefer more accessible habitats where it is easier to hide. There is not much known regarding the habitat of the genus due to their migration patterns and unique preferences. [1]
The diet of Marmosops includes, but is not limited to fruit, arthropods, flowers and small vertebrates. [16] They also will eat insects, arachnids, and gastropods depending on the species and time of the year. Their diet seems to change with the seasons, with more diversity in food preference shown in the drier seasons. Each species has a slightly different diet depending on their habitat and what is available in that area. [17]
Most of the Marmosops carry their offspring in utero and feed them through the process of lactation. [14] There is a high reproduction rate in the months of September through March for M. paulensis, with more mating occurring when there is a larger food supply. For this species, death occurred after every mating event was completed. This ensured that there was no more than one mating event for each animal that reproduced. [18] Successful breeding depends on the presence of females, and many may have multiple mating partners in order to produce more offspring if they do not die after one event. [12] The M. paulensis species have higher breeding rates when the length of day is longer and there is more fruit available to eat. Semelparity also was found to occur in this species, but is hypothesized to occur only due to phylogenic constraints. It seems as though there is synchrony of the females for the species due to swollen nipples around the time of breeding. [18] The M. incanus have also been found to exhibit semelparity with a distinct breeding season between the months of October through December. For the breeding season, it is more beneficial for the females to be larger in order to produce larger litters, yielding higher breeding success over the smaller sized females. When looking at milk production and food supply for the genus, there was a strong correlation found between the two as well. In times where there was more food, there was more milk produced by the females. [18] As far as the males, they seem to generally disappear after the mating event while the females remain in the area until their young are done weaning. This pattern leads to the generations being replaced every breeding season due to mortality of the adults. Overall, there is not much known about the reproductive patterns of the other species due to the little knowledge collected on the genus as a whole. [16] There is a lack of pouch.
The Marmosops noctivagus species have been involved in a big debate on which Genus they belong to. One study found them located in Columbia, which was previously an unknown location as far as Marmosops are concerned. They were identified by the chestnut brown hair on their back and white hair on their ventral side along with black facial features. They also have long tails with two different colors. [13] The M. noctivagus also has a skull with a long nose and cranial openings between the squamosal and parietal bones. This is present in some of the animals and absent in others. The cranial openings under the squamosal bones, also known as fenestra (anatomy), are small and rounded. [13] The dental arrangement for the species consists of large canine teeth but lack accessory cusps, correlating with the age and sex of the animal. These teeth are significantly smaller in the females. [13] The Marmosops bishopi are another species of the genus Marmosops found in the western Brazilian Amazon rainforest and other areas of Peru and Bolivia. [13] Marmosops incanus are another species in the genus that have a mask made of black fur around their eyes. Some other distinguishing characteristics include the third digit being longer than the second and the fourth along with an extremely long tail. They do not have a fenestra on the maxilla, but the fenestra cochlea is exposed [1] The Marmosops creightoni is a species that is medium in size with a coat that is almost completely dark with no clear distinction between the dorsal and ventral sides. This is the only species of the genus without the white markings on the underside. The chin fur is white and continues down to the throat along with a black mask around the eyes. The skull consists of small orbits with long nasal bones and the infraorbital foramen is very large. This species has a fenestra between the maxilla and palatine bone, which are both long and narrow on each side. The palatine fenestra are rather small in size. [1] The M. handleyi is one last species with very little known about it. However, rather recently there has been new information uncovered. The species is characterized by its woody dorsal fur, gray ventral fur and a rounded palatine fenestra. They are intermediately sized compared to the rest of the genus and have dark black facial masks. They were found to lack throat glands as well. They have white or light gray ears and the females are unique due to the odd rusty-red color of their mammary area with seven nipples located on the abdominal region. [19]
Opossums are members of the marsupial order Didelphimorphia endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North America in the Great American Interchange following the connection of North and South America.
The bare-tailed woolly mouse opossum or short-furred woolly mouse opossum is a South American marsupial of the family Didelphidae. Its range includes Brazil, Colombia, Ecuador, Peru, and Bolivia. It is found in tropical rainforest in the westernmost portion of the Amazon Basin and the eastern foothills of the Andes, at elevations up to 1634 m. It was formerly assigned to the genus Micoureus, which was made a subgenus of Marmosa in 2009. Some sources, such as the American Society of Mammalogists, believe this species is a synonym of the Isthmian mouse opossum.
The delicate slender opossum is a small pouchless marsupial of the family Didelphidae that occurs in French Guiana, Guyana, Suriname, and adjacent Venezuela and Brazil. Marmosops pinheiroi, Marmosops bishopi and Marmosops juninensis had long been considered to represent the same species, until parvidens and pinheiroi were found in sympatry in French Guiana. This species is found in moist primary tropical rainforest at elevations up to 2000 m. It is nocturnal and partially arboreal, and feeds on insects and fruit.
The southeastern four-eyed opossum is an opossum species native to South America. It is found in Atlantic Forest ecoregions, in Brazil, Paraguay and Argentina.
The 27 species in the genus Marmosa are relatively small Neotropical members of the family Didelphidae. This genus is one of three that are known as mouse opossums. The others are Thylamys and Tlacuatzin, the grayish mouse opossum. Members of the genus Marmosops used to be called "slender mouse opossums", but are now just called "slender opossums". The thirteen members of the Marmosa subgenus Micoureus, known as woolly mouse opossums, were formerly considered to be a separate genus, but were moved into Marmosa in 2009. Based on a comparison of sequences of one mitochondrial and three nuclear genes, three new subgenera, Eomarmosa, Exulomarmosa and Stegomarmosa, were recognized by Voss et al. in 2014. Eomarmosa and Exulomarmosa, as well as Marmosa and Micoureus, are thought to be sister taxa, while Stegomarmosa is viewed as sister to Marmosa plus Micoureus. Exulomarmosa is a mostly trans-Andean clade.
The nine species in the genus Philander, commonly known as gray and black four-eyed opossums, are members of the order Didelphimorphia. Mature females have a well-developed marsupium. The tail appears to be hairless except for the proximal 5 or 6 cm, which has a few long hairs. The tail is slightly longer than the head-and-body length, and it is black for the proximal one half to two thirds of its length. The genus is closely related to Didelphis but the species of Philander are smaller than those of Didelphis. The genus formerly included Metachirus nudicaudatus, but this species lacks a pouch and so is now considered a separate genus. The common name comes from the white spots above the eyes, which can appear from a distance to be another set of eyes.
The agile gracile opossum, is an opossum species from South America. It is found in Argentina, Bolivia, Brazil, Colombia, Peru, Paraguay, and Uruguay.
The gray slender opossum, is an opossum species endemic to eastern Brazil.
The white-bellied slender opossum is a species of opossum from South America. It is found in Bolivia, Brazil, Ecuador and Peru.
The Brazilian slender opossum is an opossum species from South America. It is found in moist montane forest in the Atlantic Forest region of southeastern Brazil, including the states of Minas Gerais, Rio de Janeiro, São Paulo and Paraná. Its breeding may be fully semelparous, which is unusual for a mammal.
The pygmy short-tailed opossum, scientifically named Monodelphis kunsi, is an opossum species from South America. M. kunsi is a marsupial from the family Didelphidae of the order Didelphimorphia. Although it is a marsupial, it lacks the characteristic pouch that is often associated with this order. It is found in Argentina, Bolivia, Brazil and Paraguay. M. kunsi is considered a smaller species within the family Didelphidae, which is why it is named a pygmy opossum. The young are referred to as 'joeys'. The females are referred to as 'Jill,' and the males 'jack'. It was thought to have been endangered in 2001, but has since been moved to least concern by the International Union for Conservation of Nature.
Handley's slender opossum is a species of opossum in the family Didelphidae. It is endemic to Colombia.
Gracilinanus is a genus of opossum in the family Didelphidae. It was separated from the genus Marmosa in 1989, and has since had the genera Cryptonanus, Chacodelphys, and Hyladelphys removed from it.
The Didelphinae are a subfamily of opossums consisting of 15 genera and 123 species. Specimens have been collected throughout the Americas, but are predominant in South and Central America.
Bishop's slender opossum is a small, arboreal marsupial opossum native to Brazil, Peru, and Bolivia. It somewhat resembles a placental rat or shrew.
The Argentine fat-tailed mouse opossum was formerly considered a species of opossum in the family Didelphidae. It is found in the eastern foothills of the Andes in northern Argentina and southern Bolivia. Typically reach around 10-13 cm in body length, with a bushy tail adding another 12-15 cm. Its dorsal fur is gray brown to dark brown. Its ventral fur is gray-based except for the white to yellowish chest hairs. It has been distinguished from T. cinderella by its postorbital ridges. T. cinderella has well-developed postorbital ridges in both juveniles and adults that extend laterally behind the eye sockets. Only adults of T. sponsorius have fully developed postorbital ridges, and these do not extend laterally behind the eye sockets. While the American Society of Mammalogists maintains this as a distinct species, mitochondrial DNA sequence analysis does not support the population being distinct from T. cinderella.
Mondolfi's four-eyed opossum is a South American species of opossum found in Colombia and Venezuela, first described in 2006. It inhabits foothills of the Cordillera de Mérida and those on the eastern side of the Cordillera Oriental at elevations from 50 to 800 m. Populations in the two ranges may represent distinct subspecies. It is named after the Venezuelan biologist Edgardo Mondolfi. It has short woolly fur with a pale cream-colored venter as well as large ears pigmented on only the distal half. It is considered to be a junior synonym of the common four-eyed opossum by some sources, such as the Mammal Diversity Database.
The montane Atlantic Forest rat is a South American rodent species of the family Cricetidae. It is endemic to part of the Atlantic Forest region of southeastern Brazil, where it is found at elevations from 1000 to 2700 m in noncontiguous mountain ranges. Its karyotype, like that of closely related Delomys dorsalis, has 2n = 82, but the fundamental numbers of the two species differ. While it is not thought to be in present danger of extinction, habitat destruction and grassland fires are considered to be threats.