Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of the defining features of marsupials is their unique reproductive strategy, where the young are born in a relatively undeveloped state and then nurtured within a pouch on their mother's abdomen.
Hippopotamidae is a family of stout, naked-skinned, and semiaquatic artiodactyl mammals, possessing three-chambered stomachs and walking on four toes on each foot. While they resemble pigs physiologically, their closest living relatives are the cetaceans. They are sometimes referred to as hippopotamids.
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.
Paucituberculata is an order of South American marsupials. Although currently represented only by the seven living species of shrew opossums, this order was formerly much more diverse, with more than 60 extinct species named from the fossil record, particularly from the late Oligocene to early Miocene epochs. The earliest paucituberculatans date to the late Paleocene. The group went through a pronounced decline in the middle Miocene epoch, which resulted in the extinction of all families of this order except for the living shrew opossums (Caenolestidae). Extinct families of Paucituberculatans include Pichipilidae, Palaeothentidae, and Abderitidae.
The long-nosed caenolestid, also known as the Chilean shrew opossum or long-nosed shrew opossum, is a shrew opossum that occurs in temperate forests of Argentina and southern Chile. It was first described by American zoologist Wilfred Hudson Osgood in 1924. The long-nosed caenolestid resembles Caenolestes species in morphology. It is characterized by a long, pointed snout, small eyes and ears, and one claw on a digit of each of the thin limbs. Little is known of its behavior; it appears to be terrestrial, nocturnal and omnivorous. It prefers cool, moist areas, and has a small distribution. It is classified as near threatened by the IUCN.
Didelphis is a genus of New World marsupials. The six species in the genus Didelphis, commonly known as Large American opossums, are members of the opossum order, Didelphimorphia.
The dusky caenolestid, also known as Tate's shrew opossum, is a shrew opossum from South America. The dusky caenolestid is characterized by a dark brown coat with a lighter underbelly, soft and thick fur, and a loosely haired tail. A nocturnal animal, the dusky caenolestid lives on trees and feeds on insects and small invertebrates and vertebrates. It occurs in alpine and páramo forests in northern and western Colombia, Ecuador, and western Venezuela. The IUCN classifies this shrew opossum as least concern.
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.
Monodelphis is a genus of marsupials in the family Didelphidae, commonly referred to as short-tailed opossums. They are found throughout South America. As of January 2019, the most recently described species is M. vossi.
The common shrew opossums are members of the family Caenolestidae. They are found in Colombia, Ecuador, Peru, and Venezuela. The most recently discovered species is C. sangay.
The marsupial family Peramelidae contains the extant bandicoots. They are found throughout Australia and New Guinea, with at least some species living in every available habitat, from rainforest to desert. Four fossil peramelids are described. One known extinct species of bandicoot, the pig-footed bandicoot, was so different from the other species, it was recently moved into its own family.
Thylamys is a genus of opossums in the family Didelphidae. The premaxillae are rounded rather than pointed. The females lack a pouch. The females' nipples are arranged in two symmetrical rows on the abdomen. All species but T. macrurus store fat in their tails., although this is not necessarily true for all species in the genus. Fossils belonging to the genus date back to the Miocene, with the oldest specimens being found in the Cerro Azul Formation of Argentina and the Honda Group of Colombia. Genetic studies indicate that the genus may have originated around 14 million years ago.
The gray-bellied caenolestid, or grey-bellied shrew opossum, is a shrew opossum found in humid, temperate forests and moist grasslands of western Ecuador and northwestern Peru. It was first described by American zoologist Harold Elmer Anthony in 1921. Little is known about the behavior of the gray-bellied caenolestid. It appears to be terrestrial (land-living) and crepuscular or nocturnal. Diet consists of invertebrate larvae, small vertebrates and plant material. The IUCN classifies the gray-bellied caenolestid as near threatened.
The northern caenolestid, also known as the blackish shrew opossum, is a shrew opossum found in Colombia and Ecuador. It is listed as Vulnerable by the IUCN.
The Incan caenolestid, also known as the Incan shrew opossum or Peruvian caenolestid, is a caenolestid found in the southern Peruvian Andes. It was first described by English zoologist Oldfield Thomas in 1917. The head-and-body length ranges from 9 to 11.5 centimetres, and the weight is between 25 and 32 grams. It is brown on the back, and lighter on the underside. Little is known about the behaviour of the Incan caenolestid; it appears to be terrestrial and nocturnal. It feeds on small invertebrates and insects. This caenolestid inhabits elfin and secondary forests. The IUCN classifies it as least concern.
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 Andean caenolestid, also known as the Andean shrew opossum or Condor caenolestid, is a shrew opossum known only from Cordillera del Cóndor (Ecuador), its type locality. It was first described by zoologists Bruce D. Patterson and Luis Albuja in 1996. It is the largest caenolestid. The IUCN classifies it as vulnerable. As of 2015, the population is estimated at less than 1,000.
Cryptonanus is a genus of opossums from South America. It includes five species found from Bolivia to Uruguay and eastern Brazil, one of which is now extinct. Although the first species were discovered in 1931, the genus was not recognized as distinct from Gracilinanus until 2005. It includes small opossums with generally grayish, sometimes reddish, fur that are mainly distinguished from other opossums by characters of the skull.
Chlamyphorinae is a subfamily of South American armadillos in the family Chlamyphoridae. Members of this subfamily, the fairy armadillos, are largely fossorial and have reduced eyes and robust forearms with large claws for digging.
The eastern caenolestid is a shrew opossum found on the eastern slopes of the Andes in southern Ecuador.
