The Spalacidae, or spalacids, are a
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
of
rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...
s in the large and complex
superfamily
SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...
Muroidea
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 excep ...
. They are native to eastern
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...
, the
Horn of Africa
The Horn of Africa (HoA), also known as the Somali Peninsula, is a large peninsula and geopolitical region in East Africa.Robert Stock, ''Africa South of the Sahara, Second Edition: A Geographical Interpretation'', (The Guilford Press; 2004 ...
, the
Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
, and southeastern
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
. It includes the
blind mole-rats,
bamboo rats,
mole-rats, and
zokors. This family represents the oldest split (excluding perhaps the
Platacanthomyidae) 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
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...
group. Members of the Spalacidae are often placed in the family
Muridae
The Muridae, or murids, are the largest family of rodents and of mammals, containing approximately 1,383 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia.
The name Muridae comes ...
along with all other members of the Muroidea.
Characteristics
Spalacids are
mouse
A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...
- to
rat-sized rodents, adapted to burrowing and living underground. They have short limbs, wedge-shaped skulls, strong neck muscles, large
incisor
Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wher ...
teeth, and small eyes and
external ears. In the zokors, which dig primarily with their feet, rather than their teeth, the front
claw
A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or tarsus ...
s are also massively enlarged. These features are least extreme in the bamboo rats, which spend at least some of their time above ground, foraging for food. They are most highly developed in the blind mole-rats, whose eyes are completely covered by skin, and entirely lack external ears or tails.
All of the spalacid species dig extensive burrows, which may include storage chambers for food,
latrine
A latrine is a toilet or an even simpler facility that is used as a toilet within a sanitation system. For example, it can be a communal trench in the earth in a camp to be used as emergency sanitation, a hole in the ground ( pit latrine), or ...
chambers, and breeding nests. They are generally solitary animals, and do not share their tunnel complexes with other individuals. All the species are
herbivore
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpar ...
s, feeding on
root
In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the su ...
s, bulbs, and
tuber
Tubers are a type of enlarged structure used as storage organs for nutrients in some plants. They are used for the plant's perennation (survival of the winter or dry months), to provide energy and nutrients for regrowth during the next growing ...
s.
They give birth to litters of up to six young after a
gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pr ...
period between three and seven weeks, depending on the species. As with many other muroids, the young are born blind, hairless, and helpless. They may stay with the mother for several months before setting off to establish their own burrows, although some species disperse as soon as they are
weaned.
Characteristics
Norris ''et al.''
listed several characteristics present in all members of this family which distinguish them from the rest of the muroids, (the
clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...
Eumuroida). These are "the reduction or absence of external eyes, reduced pinnae, stocky body, short tail (<50% head and body length), broad
rostrum, triangular-shaped braincase,
infraorbital canal
The infraorbital canal is a canal found at the base of the orbit that opens on to the maxilla. It is continuous with the infraorbital groove and opens onto the maxilla at the infraorbital foramen. The infraorbital nerve and infraorbital arte ...
ovoid shape and does not extend
ventral
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...
ly to the roof of the
palate
The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity.
A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly separ ...
,
zygomatic plate absent or much reduced, nasolacrimal canal inside
infraorbital canal
The infraorbital canal is a canal found at the base of the orbit that opens on to the maxilla. It is continuous with the infraorbital groove and opens onto the maxilla at the infraorbital foramen. The infraorbital nerve and infraorbital arte ...
,
incisive foramina
In the human mouth, the incisive foramen (also known as: "''anterior palatine foramen''", or "''nasopalatine foramen''") is the opening of the incisive canals on the hard palate immediately behind the incisor teeth. It gives passage to blood vesse ...
small to medium-sized, extensive neck musculature and prominent points of attachment on the occipitum, minimal reduction in M3 relative to M1 and M2, and a distinct orientation of the manubrium of the
malleus bone."
Classification
The spalacids are classified in three
subfamilies, six
genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
, and 37
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
.
Family Spalacidae
*Subfamily
Myospalacinae - zokors
**Genus ''
Myospalax''
***''Myospalax myospalax'' species group
****
False zokor, ''M. aspalax''
****
Siberian zokor, ''M. myospalax''
***''Myospalax psilurus'' species group
****
Transbaikal zokor, ''M. psilurus''
**Genus ''
Eospalax''
***
Chinese zokor, ''E. fontanierii''
***
Rothschild's zokor
The Rothschild's zokor (''Eospalax rothschildi'') is a species of rodent in the family 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 o ...
, ''E. rothschildi''
***
Smith's zokor
Smith's zokor (''Eospalax smithii'') is a species of rodent in the family 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 ...
, ''E. smithii''
*Subfamily
Rhizomyinae
**Tribe
Rhizomyini - bamboo rats
***Genus ''
Rhizomys
''Rhizomys'', also known as bamboo rat, is a genus of rodents in the family 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, ...
''
****
Hoary bamboo rat
The hoary bamboo rat (''Rhizomys pruinosus'') is a species of rodent in the family Spalacidae found in Southeast Asia (Cambodia, Laos, Malaysia, Myanmar, Thailand, and Vietnam), East Asia ( China) and South Asia (India).
Description
The hoary b ...
, ''R. pruinosus''
****
Chinese bamboo rat
The Chinese bamboo rat (''Rhizomys sinensis'') is a species of rodent in the family Spalacidae found in southern China, northern Myanmar, and northern Vietnam. Its habitat is bamboo thickets usually at high elevations, pine forests, and plantati ...
, ''R. sinensis''
****
Large bamboo rat
The large bamboo rat, Sumatran rat, or Indomalayan rat (''Rhizomys sumatrensis'') is a species of rodent in the family Spalacidae found in Cambodia, China, Indonesia, Laos, Malaysia, Myanmar, Thailand, and Vietnam. It is one of four species of b ...
, ''R. sumatrensis''
***Genus ''
Cannomys
The lesser bamboo rat (''Cannomys badius'') is a species of rodent in the family Spalacidae. It is monotypic within the genus ''Cannomys''. It is found in Bangladesh, Bhutan, Cambodia, China, India, Myanmar, Nepal, and Thailand.
Description
Th ...
''
****
Lesser bamboo rat, ''C. badius''
***†Genus ''
Brachyrhizomys'' (Miocene to Pleistocene)
**Tribe
Tachyoryctini
***Genus ''
Tachyoryctes'' - African mole-rats
****
Ankole African mole-rat
The Ankole mole-rat or Ankole African mole-rat (''Tachyoryctes ankoliae'') is a species of rodent in the family Spalacidae found in southwestern Uganda and northwestern Tanzania. Its natural habitats are moist savanna and arable land. Some taxono ...
, ''T. ankoliae''
****
Mianzini African mole-rat
The Mianzini mole-rat or Mianzini African mole-rat (''Tachyoryctes annectens'') is a species of rodent in the family Spalacidae endemic to Kenya. Its natural habitats are dry savanna, pastureland, and rural gardens. Some taxonomic authorities co ...
, ''T. annectens''
****
Aberdare Mountains African mole-rat
The Aberdare Mountains African mole-rat (''Tachyoryctes audax'') is a species of rodent in the family Spalacidae endemic to Kenya. Its natural habitats are subtropical or tropical moist montane forests and subtropical or tropical high-altitude g ...
, ''T. audax''
****
Demon African mole-rat
The northeast African mole-rat (''Tachyoryctes splendens'') is a species of rodent in the family Spalacidae and is found in Ethiopia, Somalia, and northwest Kenya. Its natural habitats are subtropical or tropical moist montane forests, dry savann ...
, ''T. daemon''
****
Kenyan African mole-rat
The Kenyan African mole-rat or Kenyan mole-rat (''Tachyoryctes ibeanus'') is a species of rodent in the family Spalacidae. It is endemic to Kenya. Its natural habitats are dry savanna, moist savanna, arable land, pastureland, plantations, rural g ...
, ''T. ibeanus''
****
Big-headed African mole-rat
The big-headed African mole rat, (''Tachyoryctes macrocephalus''), also known as the giant root-rat, Ethiopian African mole rat, or giant mole rat, is a rodent species in the family Spalacidae.
It is endemic to Ethiopia's Bale Mountains. Its nat ...
, ''T. macrocephalus''
****
Navivasha African mole-rat
The Naivasha African mole-rat (''Tachyoryctes naivashae'') is a species of rodent in the family Spalacidae. It is endemic to Kenya. Its natural habitats are subtropical or tropical moist montane forests, moist savanna, arable land, and pas ...
, ''Tachyoryctes naivashae''
****
King African mole-rat
The King African mole-rat,Musser and Carleton, 2005, p. 924 King mole-rat, or Alpine mole-rat, (''Tachyoryctes rex'') is a burrowing rodent in the genus ''Tachyoryctes'' of family Spalacidae. It only occurs high on Mount Kenya, where it is ...
, ''T. rex''
****
Rwanda African mole-rat, ''T. ruandae''
****
Rudd's African mole-rat, ''T. ruddi''
****
Embi African mole-rat, ''T. spalacinus''
****
Northeast African mole-rat
The northeast African mole-rat (''Tachyoryctes splendens'') is a species of rodent in the family Spalacidae and is found in Ethiopia, Somalia, and northwest Kenya. Its natural habitats are subtropical or tropical moist montane forests, dry ...
, ''T. splendens''
****
Storey's African mole-rat, ''T. storeyi''
*Subfamily
Spalacinae - blind mole-rats
**Genus ''
Spalax''
***
Mehely's blind mole-rat
Mehely's blind mole-rat (''Spalax antiquus'') is an endangered species of rodent in the family Spalacidae. It is endemic to Romania.
Taxonomy
Previously described in 1909 by Lajos Méhelÿ as a subspecies of the Balkan mole-rat (''S. grae ...
'', S. antiquus''
***
Sandy blind mole-rat, ''S. arenarius''
***
Giant blind mole-rat, ''S. giganteus''
***
Bukovina blind mole-rat, ''S. graecus''
***
Oltenia blind mole-rat
The Oltenia blind mole-rat (''Spalax istricus'') is a critically endangered, possibly extinct species of rodent in the family Spalacidae. It is endemic to Romania.
Taxonomy
Previously described in 1909 by Lajos Méhelÿ as a subspecies of ...
, ''S. istricus'' (possibly
extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
)
***
Greater blind mole-rat
The greater blind mole-rat (''Spalax microphthalmus'') is a species of rodent in the family Spalacidae. It is found in Russia and Ukraine.
Description
The greater blind mole-rat is tailless. The eyes are covered by a membrane of skin and have ...
, ''S. microphthalmus''
***
Kazakhstan blind mole-rat, ''S. uralensis''
***
Podolsk blind mole-rat
The Podolsk blind mole-rat or Podolian mole-rat (''Spalax zemni'') is a species of rodent in the family Spalacidae. It is endemic to western and central Ukraine.
Distribution and habitat
It has a wide but severely fragmented range throughou ...
, ''S. zemni''
**Genus ''
Nannospalax
''Nannospalax'' is a genus of rodent in the family Spalacidae, found in eastern Europe and western Asia. It is one of two genera in the blind mole-rats (subfamily Spalacinae), alongside ''Spalax''. Members of this genus are also known as small-bod ...
'' - small-bodied mole-rats
***Subgenus ''Nannospalax''
****
Middle East blind mole-rat or Palestine mole-rat, ''N. ehrenbergi''
***Subgenus ''Mesospalax''
****
Lesser blind mole-rat, ''N. leucodon''
****
Anatolian blind mole-rat or Nehring's blind mole-rat, ''N. xanthodon''
References
*Jansa, S. A. and M. Weksler. 2004. Phylogeny of muroid rodents: relationships within and among major lineages as determined by IRBP
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
sequences. Molecular Phylogenetics and Evolution, 31:256-276.
*Michaux, J., A. Reyes, and F. Catzeflis. 2001. Evolutionary history of the most speciose mammals: molecular phylogeny of muroid rodents. Molecular Biology and Evolution, 17:280-293.
*Steppan, S. J., R. A. Adkins, and J. Anderson. 2004. Phylogeny and
divergence date estimates of rapid radiations in muroid rodents based on multiple nuclear genes. Systematic Biology, 53:533-553.
{{Taxonbar, from=Q557935
Rodent families
Muroid rodents
Extant Miocene first appearances
Taxa named by John Edward Gray