Cricetidae
Encyclopedia
The Cricetidae are a family
of rodent
s in the large and complex superfamily Muroidea
. It includes true hamster
s, vole
s, lemming
s, and New World rats and mice
. At almost 600 species, it is the second largest family
of mammal
s, and has members throughout the New World, Asia, and Europe.
up to 41 centimetre and 1100 g (38.8 oz) in the Muskrat
. The length of the tails varies greatly in relation to the body, and they may be either furred or sparsely haired. The fur of most species is brownish in colour, often with a white underbelly, but many other patterns exist, especially in the cricetine and arvicoline
subfamilies.
Like the Old World Mice
, cricetids are adapted to a wide range of habitats, from the high Arctic
to tropical rainforest
s and hot desert
s. Some are arboreal, with long balancing tails and other adaptations for climbing, while others are semiaquatic, with webbed feet and small external ears. Yet others are burrowing animals, or ground-dwellers.
Their diet is similarly variable, with herbivorous
, omnivorous
, and insectivorous
species all being known. They all have large, gnawing, incisor
s separated from grinding molar
teeth by a gap, or diastema
. Although there are a few exceptions, the dental formula
for the great majority of cricetids is:
Cricetids' populations can increase rapidly in times of plenty, due to a combination of short gestation
period of between 15 and 50 days, and large litter sizes relative to many other mammals. The young are typically born blind, hairless, and helpless.
The cricetids first evolved in the Old World during the Miocene
. They soon adapted to a wide range of habitats, and spread throughout the world. The voles and lemmings arose later, during the Pliocene
, and rapidly diversified during the Pleistocene
.
The term Cricetidae has gone through several permutations, and members of the family as currently defined are often placed in the family Muridae
along with all other muroid
subfamilies. Many other muroids
have been called members of the Cricetidae in the past such as mouse-like hamster
s (subfamily Calomyscinae, family Calomyscidae), gerbil
s (subfamily Gerbillinae, family Muridae
), the crested rat (subfamily Lophiomyinae, family Muridae
), zokor
s (subfamily Myospalacinae, family Spalacidae
), the white-tailed rat (subfamily Mystromyinae, family Nesomyidae
), and spiny dormice (subfamily Platacanthomyinae
, family Platacanthomyidae). Multigene DNA sequence
studies have shown that the subfamilies listed below are related (i.e. form a monophyletic group), and that the other muroids should not be included in the Cricetidae.
The cricetids are thus classified to contain one prehistoric and 5 living subfamilies, around 112 living genera
and approximately 580 living species
:
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s in the large and complex superfamily Muroidea
Muroidea
Muroidea is a large superfamily of rodents. It includes hamsters, gerbils, true mice and rats, and many other relatives. 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...
. It includes true hamster
Hamster
Hamsters are rodents belonging to the subfamily Cricetinae. The subfamily contains about 25 species, classified in six or seven genera....
s, vole
Vole
A vole is a small rodent resembling a mouse but with a stouter body, a shorter hairy tail, a slightly rounder head, smaller ears and eyes, and differently formed molars . There are approximately 155 species of voles. They are sometimes known as meadow mice or field mice in North America...
s, lemming
Lemming
Lemmings are small rodents, usually found in or near the Arctic, in tundra biomes. They are subniveal animals, and together with voles and muskrats, they make up the subfamily Arvicolinae , which forms part of the largest mammal radiation by far, the superfamily Muroidea, which also includes rats,...
s, and New World rats and mice
New World rats and mice
The New World rats and mice are a group of related rodents found in North and South America. They are extremely diverse in appearance and ecology, ranging in from the tiny Baiomys to the large Kunsia...
. At almost 600 species, it is the second largest family
Family
In human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence. In most societies it is the principal institution for the socialization of children...
of mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s, and has members throughout the New World, Asia, and Europe.
Characteristics
The cricetids are small mammals, ranging from just 5 centimetre in length and 7 g (0.246917734735784 oz) in weight in the New World Pygmy MouseBaiomys
Baiomys is the genus of New World pygmy mice. Together with Scotinomys, it forms the tribe Baiomyini. It currently contains two extant species:*Southern Pygmy Mouse, Baiomys musculus*Northern Pygmy Mouse, Baiomys taylori-References:...
up to 41 centimetre and 1100 g (38.8 oz) in the Muskrat
Muskrat
The muskrat , the only species in genus Ondatra, is a medium-sized semi-aquatic rodent native to North America, and introduced in parts of Europe, Asia, and South America. The muskrat is found in wetlands and is a very successful animal over a wide range of climates and habitats...
. The length of the tails varies greatly in relation to the body, and they may be either furred or sparsely haired. The fur of most species is brownish in colour, often with a white underbelly, but many other patterns exist, especially in the cricetine and arvicoline
Arvicolinae
The Arvicolinae are a subfamily of rodents that includes the voles, lemmings, and muskrats. They are most closely related to the other subfamilies in the Cricetidae . Some authorities place the subfamily Arvicolinae in the family Muridae along with all other members of the superfamily Muroidea...
subfamilies.
Like the Old World Mice
Muridae
Muridae is the largest family of mammals. It contains over 600 species found naturally throughout Eurasia, Africa, and Australia. They have been introduced worldwide. The group includes true mice and rats, gerbils, and relatives....
, cricetids are adapted to a wide range of habitats, from the high Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...
to tropical rainforest
Rainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
s and hot desert
Desert
A desert is a landscape or region that receives an extremely low amount of precipitation, less than enough to support growth of most plants. Most deserts have an average annual precipitation of less than...
s. Some are arboreal, with long balancing tails and other adaptations for climbing, while others are semiaquatic, with webbed feet and small external ears. Yet others are burrowing animals, or ground-dwellers.
Their diet is similarly variable, with herbivorous
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
, omnivorous
Omnivore
Omnivores are species that eat both plants and animals as their primary food source...
, and insectivorous
Insectivore
An insectivore is a type of carnivore with a diet that consists chiefly of insects and similar small creatures. An alternate term is entomophage, which also refers to the human practice of eating insects....
species all being known. They all have large, gnawing, incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s separated from grinding molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
teeth by a gap, or diastema
Diastema (dentistry)
Diastema is a space or gap between two teeth. Many species of mammals have diastemata as a normal feature, most commonly between the incisors and molars.-In humans:...
. Although there are a few exceptions, the dental formula
Dentition
Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, the characteristic arrangement, kind, and number of teeth in a given species at a given age...
for the great majority of cricetids is:
Cricetids' populations can increase rapidly in times of plenty, due to a combination of short gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
period of between 15 and 50 days, and large litter sizes relative to many other mammals. The young are typically born blind, hairless, and helpless.
Evolution and systematics
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
. They soon adapted to a wide range of habitats, and spread throughout the world. The voles and lemmings arose later, during the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
, and rapidly diversified during the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
.
The term Cricetidae has gone through several permutations, and members of the family as currently defined are often placed in the family Muridae
Muridae
Muridae is the largest family of mammals. It contains over 600 species found naturally throughout Eurasia, Africa, and Australia. They have been introduced worldwide. The group includes true mice and rats, gerbils, and relatives....
along with all other muroid
Muroidea
Muroidea is a large superfamily of rodents. It includes hamsters, gerbils, true mice and rats, and many other relatives. 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...
subfamilies. Many other muroids
Muroidea
Muroidea is a large superfamily of rodents. It includes hamsters, gerbils, true mice and rats, and many other relatives. 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...
have been called members of the Cricetidae in the past such as mouse-like hamster
Mouse-like hamster
thumb|200px|rightthumb|200px|right|Mouse-like hamster using its tail for balance while standing on a branch .Mouse-like hamsters are a group of small rodents found in Syria, Azerbaijan, Iran, Turkmenistan, Afghanistan, and Pakistan...
s (subfamily Calomyscinae, family Calomyscidae), gerbil
Gerbil
A gerbil is a small mammal of the order Rodentia. Once known simply as "desert rats", the gerbil subfamily includes about 110 species of African, Indian, and Asian rodents, including sand rats and jirds, all of which are adapted to arid habitats...
s (subfamily Gerbillinae, family Muridae
Muridae
Muridae is the largest family of mammals. It contains over 600 species found naturally throughout Eurasia, Africa, and Australia. They have been introduced worldwide. The group includes true mice and rats, gerbils, and relatives....
), the crested rat (subfamily Lophiomyinae, family Muridae
Muridae
Muridae is the largest family of mammals. It contains over 600 species found naturally throughout Eurasia, Africa, and Australia. They have been introduced worldwide. The group includes true mice and rats, gerbils, and relatives....
), zokor
Zokor
Zokors are Asiatic burrowing rodents resembling mole rats. They include two genera, Myospalax and Eospalax. Zokors are native to much of China, Kazhakstan, and Siberian Russia....
s (subfamily Myospalacinae, family Spalacidae
Spalacidae
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 south-eastern Europe. It includes the blind mole rats, bamboo rats, root rats, and zokors...
), the white-tailed rat (subfamily Mystromyinae, family Nesomyidae
Nesomyidae
Nesomyidae is 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...
), and spiny dormice (subfamily Platacanthomyinae
Platacanthomyinae
The rodent family Platacanthomyidae, or Oriental dormice, includes the spiny dormice and the Chinese pygmy dormice. In spite of their appearance, these animals are not true dormice, but are part of the large and complex superfamily Muroidea...
, family Platacanthomyidae). Multigene DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
studies have shown that the subfamilies listed below are related (i.e. form a monophyletic group), and that the other muroids should not be included in the Cricetidae.
The cricetids are thus classified to contain one prehistoric and 5 living subfamilies, around 112 living genera
Genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...
and approximately 580 living species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
:
- ArvicolinaeArvicolinaeThe Arvicolinae are a subfamily of rodents that includes the voles, lemmings, and muskrats. They are most closely related to the other subfamilies in the Cricetidae . Some authorities place the subfamily Arvicolinae in the family Muridae along with all other members of the superfamily Muroidea...
— voleVoleA vole is a small rodent resembling a mouse but with a stouter body, a shorter hairy tail, a slightly rounder head, smaller ears and eyes, and differently formed molars . There are approximately 155 species of voles. They are sometimes known as meadow mice or field mice in North America...
s, lemmingLemmingLemmings are small rodents, usually found in or near the Arctic, in tundra biomes. They are subniveal animals, and together with voles and muskrats, they make up the subfamily Arvicolinae , which forms part of the largest mammal radiation by far, the superfamily Muroidea, which also includes rats,...
s, muskratMuskratThe muskrat , the only species in genus Ondatra, is a medium-sized semi-aquatic rodent native to North America, and introduced in parts of Europe, Asia, and South America. The muskrat is found in wetlands and is a very successful animal over a wide range of climates and habitats... - Cricetinae — hamsterHamsterHamsters are rodents belonging to the subfamily Cricetinae. The subfamily contains about 25 species, classified in six or seven genera....
s - DemocricetodontinaeDemocricetodontinaeDemocricetodontinae is a subfamily of fossil rodents from Miocene epoch.Democricetodontini was named by Lindsay in 1987. It is not extant. It was considered paraphyletic by Lindsay in 1987. It was reranked as the subfamily Democricetodontinae by Theocharopoulos in 2000 and was assigned to...
† (fossilFossilFossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
) - NeotominaeNeotominaeNeotominae is a subfamily of the family Cricetidae. It consists of four tribes, 16 genera, and many species of New World rats and mice, predominantly found in North America. Among them are the well-known deer mice, white-footed mice, packrats, and grasshopper mice.Neotomines are related to the...
— North American rats and mice, including deer mice, pack ratPack ratA packrat, also called a woodrat, can be any of the species in the rodent genus Neotoma. Packrats have a rat-like appearance, with long tails, large ears and large black eyes. Compared to deer mice, harvest mice and grasshopper mice, packrats are noticeably larger and are usually somewhat larger...
s, and grasshopper miceGrasshopper mouseThe genus Onychomys contains species commonly referred to as grasshopper mice. This is a genus of New World mouse only distantly related to the common house mouse, Mus musculus. There are three species. They are endemic to the United States and Mexico.Its behavior is rather distinct from other mice... - SigmodontinaeSigmodontinaeThe subfamily Sigmodontinae is one of the most diverse groups of mammals. It 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...
— New World rats and mice, predominantly South American genera such as brucieBrucieBrucepattersonius is a genus of rodents within the tribe Akodontini from southeastern South America. Also known as Brucies, the genus is named after Bruce Patterson, MacArthur Curator at the Department of Zoology , at the Field Museum of Natural History, Chicago.In 1998, Philip Hershkovitz...
s. - TylomyinaeTylomyinaeThe subfamily Tylomyinae consists of several species of New World rats and mice including the vesper and climbing rats. They are not as well known as their relatives in the subfamilies Sigmodontinae and Neotominae...
— New World climbing rats and relatives