The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. Members of this subfamily are called murines. In terms of species richness, this subfamily is larger than all mammal families except the Cricetidae and Muridae, and is larger than all mammal orders except the bats and the remainder of the rodents. [1]
The Murinae are native to Africa, Europe, Asia, and Australia. They are terrestrial placental mammals. They have also been introduced to all continents except Antarctica, and are serious pest animals. This is particularly true in island communities where they have contributed to the endangerment and extinction of many native animals. [2] [3]
Two prominent murine species have become vital laboratory animals: the brown rat and house mouse are both used as medical subjects.
The murines have a distinctive molar pattern that involves three rows of cusps instead of two, the primitive pattern seen most frequently in muroid rodents. [4]
The first known appearance of the Murinae in the fossil record is about 14 million years ago with the fossil genus Antemus . Antemus is thought to derive directly from Potwarmus , which has a more primitive tooth pattern. Likewise, two genera, Progonomys and Karnimata , are thought to derive directly from Antemus. Progonomys is thought to be the ancestor of Mus and relatives, while Karnimata was previously thought to lead to Rattus and relatives, although it is now thought to be a member of the extant tribe Praomyini. [4] [5] All of these fossils are found in the well-preserved and easily dated Siwalik fossil beds of Pakistan. The transition from Potwarmus to Antemus to Progonomys and Karnimata is considered an excellent example of anagenic evolution. [4]
Most of the Murinae have been poorly studied. Some genera have been grouped, such as the hydromyine water rats, conilurine or pseudomyine Australian mice, or the phloeomyine Southeast Asian forms. It appears as if genera from Southeast Asian islands and Australia may be early offshoots compared to mainland forms. The vlei rats in the genera Otomys and Parotomys are often placed in a separate subfamily, Otomyinae, but have been shown to be closely related to African murines in spite of their uniqueness.
Three genera, Uranomys , Lophuromys , and Acomys , were once considered to be murines, but were found to be more closely related to gerbils through molecular phylogenetics. They have been assigned a new subfamily status, Deomyinae.
Molecular phylogenetic studies of Murinae include Lecompte, et al. (2008), [6] which analyzes African murine species based on the mitochondrial cytochrome b gene and two nuclear gene fragments. Lecompte, et al. (2008) estimates that African murines colonized Africa from Asia approximately 11 million years ago during the Miocene.
The following phylogeny of 16 Murinae genera, based on molecular phylogenetic analysis of the Interphotoreceptor Retinoid Binding Protein (IRBP) gene, is from Jansa & Weksler (2004: 264). [7]
The following is a list of Murinae genus divisions ordered by the continents that they are endemic to. Most of the diversity is located in Southeast Asia and Australasia.
As of 2005, the Murinae contained 129 genera in 584 species. Musser and Carleton (2005) divided the Murinae into 29 genus divisions. They treated the Otomyinae as a separate subfamily, but all molecular analyses conducted to date have supported their inclusion in the Murinae as relatives of African genera. [7] [8] [9] [10] In a recent expedition in the Philippines, seven more Apomys mice were added and the genus was proposed to split into two subgenera - Apomys and Megapomys, based on morphological and cytochrome b DNA sequences. [11] In 2021, a major revision was taken of Praomyini. [12]
The tribes are based on the classification by the American Society of Mammalogists. [13] Some of the division placement is based on Pages et al., 2015 and Rowe et al., 2019. [2] [14]
SUBFAMILY MURINAE - Old World rats and mice
The Muroidea are a large superfamily of rodents, including mice, rats, voles, hamsters, lemmings, gerbils, and many other relatives. Although the Muroidea originated in Eurasia, they occupy a vast variety of habitats on every continent except Antarctica. Some authorities have placed all members of this group into a single family, Muridae, due to difficulties in determining how the subfamilies are related to one another. Many of the families within the Muroidea superfamily have more variations between the families than between the different clades. A possible explanation for the variations in rodents is because of the location of these rodents; these changes could have been due to radiation or the overall environment they migrated to or originated in. The following taxonomy is based on recent well-supported molecular phylogenies.
The Muridae, or murids, are either the largest or second-largest family of rodents and of mammals, containing approximately 870 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia.
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At over 870 species, it is either the largest or second-largest family of mammals, and has members throughout the Americas, Europe and Asia.
The Spalacidae, or spalacids, are a family of rodents in the large and complex superfamily Muroidea. They are native to eastern Asia, the Horn of Africa, the Middle East, and southeastern Europe. It includes the blind mole-rats, bamboo rats, mole-rats, and zokors. This family represents the oldest split in the muroid superfamily, and comprises animals adapted to a subterranean way of life. These rodents were thought to have evolved adaptations to living underground independently until recent genetic studies demonstrated they form a monophyletic group. Members of the Spalacidae are often placed in the family Muridae along with all other members of the Muroidea.
The Nesomyidae are a family of African rodents in the large and complex superfamily Muroidea. It includes several subfamilies, all of which are native to either continental Africa or to Madagascar. Included in this family are Malagasy rodents, climbing mice, African rock mice, swamp mice, pouched rats, and the white-tailed rat.
The Eumuroida are a clade defined in 2004 by Steppan et al. to describe a group of muroid rodents. The clade is not defined in the standard taxonomic hierarchy, but it is between superfamily and family.
Pouched rats are a group of African rodents in the subfamily Cricetomyinae. They are members of the family Nesomyidae, which contains other African muroids such as climbing mice, Malagasy mice, and the white-tailed rat. All nesomyids are in the superfamily Muroidea, a large and complex clade containing 1⁄4 of all mammal species. Sometimes the pouched rats are placed in the family Muridae along with all other members of the superfamily Muroidea.
The Malagasy rodents are the sole members of the subfamily Nesomyinae. These animals are the only native rodents of Madagascar, come in many shapes and sizes, and occupy a wide variety of ecological niches. There are nesomyines that resemble gerbils, rats, mice, voles, and even rabbits. There are arboreal, terrestrial, and semi-fossorial varieties.
The subfamily Deomyinae consists of four genera of mouse-like rodents that were previously placed in the subfamilies Murinae and Dendromurinae. They are sometimes called the Acomyinae, particularly in references that antedate the discovery that the link rat, Deomys ferugineus, is part of the clade. Deomyinae is the older name and therefore has priority over Acomyinae.
The earless water rat is a New Guinea rodent, part of the Hydromys group of the subfamily of Old World rats and mice (Murinae). It is the only species in the genus Crossomys. This species is probably most closely related to Baiyankamys. It is still unclear to which species this group is related. It is one of the most aquatically adapted rodents of the world.
The Luzon montane forest mouse is a species of rodent in the family Muridae, from the genus Apomys. It occurs only in the Philippines, where it has been found on the large northern island Luzon. It is most closely related to the large Mindoro forest mouse, which occurs on Mindoro. There may be another related species in the Sierra Madre, but this species is yet undescribed. The Luzon montane forest mouse is a relatively large, ground-dwelling rat with a tail that is quite short for its genus.
The large Mindoro forest mouse is a species of rodent in the family Muridae, from the genus Apomys. It is found only in the Philippines. Its natural habitat is subtropical or tropical moist montane forests. It is a large mouse with large feet, a long tail and an elongated snout which is morphologically unique within its genus. It is covered in soft fur which is mostly dark brown in colour. Its closest relative is thought to be the Luzon montane forest mouse, based on genetic and morphological similarities.
Otomyini is an Old World tribe of muroid rodents in the subfamily Murinae. Musser and Carleton (2005) granted it subfamily status (Otomyinae), but molecular studies consistently show that the otomyines evolved from within the Murinae, leading these researchers to subsume it in this subfamily, sometimes with tribal status. It includes 3 genera.
Danilo S. Balete, also known as Danny Balete, was a Filipino zoologist and biologist. His is known for his work on the Philippines' endemic mammal species. He pursued the question of what determines species diversity. The research by Balete and his team overturned previously held notions that diversity decreased in mountainous regions, showing that harsh environments could generate, rather than suppress, species diversity.
Apodemini is a tribe of muroid rodents in the subfamily Murinae. It contains two extant genera, one found throughout Eurasia and the other endemic to the Ryukyu Islands. Several fossil genera are also known from throughout Eurasia, including one large species (Rhagamys) that persisted on Sardinia and Corsica up until at least the first millennium BC, when it was likely wiped out by human activity.
Millardini is a tribe of muroid rodents in the subfamily Murinae. Species in this tribe are found in South and Southeast Asia.
Praomyini is a tribe of muroid rodents in the subfamily Murinae. Species in this tribe are found mostly throughout Sub-Saharan Africa, but one species is found in North Africa, and another is found in the Arabian Peninsula.
Arvicanthini is a tribe of muroid rodents in the subfamily Murinae. Almost all recent species in this tribe are or were found in Africa aside from one species, the Indian bush rat, which is found in South Asia and Iran. However, some fossil Golunda species from India and the genus Parapelomys are thought to have also occurred outside Africa, and one species in the fossil genus Saidomys may have also occurred in Afghanistan.
Hydromyini is a very large, diverse tribe of muroid rodents in the subfamily Murinae. They are the dominant native rodents in Australasia and one of only two native rodent groups there, the other being the R. fuscipes group of the genus Rattus in the tribe Rattini. They are also found in parts of Southeast Asia.
Rattini is a very large, diverse tribe of muroid rodents in the subfamily Murinae. They are found throughout Asia and Australasia, with a few species ranging into Europe and northern Africa. The most well-known members of this group are the true rats, several species of which have been introduced worldwide.