Spalacidae

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Spalacidae
Temporal range: Early Miocene–Recent
Lesser bamboo rat.jpg
Lesser bamboo rat, Cannomys badius
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Superfamily: Muroidea
Family: Spalacidae
Gray, 1821
Type genus
Spalax
Subfamilies

Spalacinae
Myospalacinae
Rhizomyinae

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 (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 group.[ citation needed ] Members of the Spalacidae are often placed in the family Muridae along with all other members of the Muroidea.

Contents

Characteristics

Spalacids are mouse- to rat-sized rodents, adapted to burrowing and living underground. They have short limbs, wedge-shaped skulls, strong neck muscles, large incisor teeth, and small eyes and external ears. In the zokors, which dig primarily with their feet, rather than their teeth, the front claws 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 chambers, and breeding nests. They are generally solitary animals, and do not share their tunnel complexes with other individuals. All the species are herbivores, feeding on roots, bulbs, and tubers.

They give birth to litters of up to six young after a gestation 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. [1]

Characteristics

Norris et al. [2] listed several characteristics present in all members of this family which distinguish them from the rest of the muroids, (the clade 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 ovoid shape and does not extend ventrally to the roof of the palate, zygomatic plate absent or much reduced, nasolacrimal canal inside infraorbital canal, incisive foramina 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, and 37 species.

Family Spalacidae

Related Research Articles

Mole-rat or mole rat refers to several groups of burrowing Old World rodents:

Rhizomyinae Subfamily of rodents

The rodent subfamily Rhizomyinae includes the Asian bamboo rats and certain of the African mole-rats. The subfamily is grouped with the Spalacinae and the Myospalacinae into a family of fossorial muroid rodents basal to the other Muroidea.

Muroidea Superfamily of rodents

The Muroidea are a large superfamily of rodents, including mice, rats, voles, hamsters, gerbils, 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 difficulties in determining how the subfamilies are related to one another. The following taxonomy is based on recent well-supported molecular phylogenies.

Zokor Subfamily of rodents

Zokors are Asiatic burrowing rodents resembling mole-rats. They include two genera: Myospalax and Eospalax. Zokors are native to much of China, Kazakhstan, and Siberian Russia.

Muridae Family of rodents

The Muridae, or murids, are the largest family of rodents and of mammals, containing approximately 1383 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia.

Cricetidae Family of rodents

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 almost 608 species, it is the second-largest family of mammals, and has members throughout the Americas, Europe and Asia.

Platacanthomyidae Family of rodents

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. The platacanthomyids can be distinguished from the true dormice, because they have no premolars, giving them three cheek teeth, like their relatives, the Muroidea.

Nesomyidae Family of rodents

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 rats and mice, climbing mice, African rock mice, swamp mice, pouched rats, and the white-tailed rat.

Eumuroida Clade of rodents

The Eumuroida are a clade defined in 2004 by Steppan et al. that includes rats, mice and related species, though not all rodents; in other words, a specific group of muroid rodents. The clade is not defined in the standard taxonomic hierarchy, but it is between superfamily and family.

Pouched rat Subfamily of rodents

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 14 of all mammal species. Sometimes the pouched rats are placed in the family Muridae along with all other members of the superfamily Muroidea.

<i>Spalax</i> Genus of rodents

Spalax is a genus of rodent in the family Spalacidae. It is one of two extant genera in the subfamily Spalacinae, alongside Nannospalax.

Blind mole-rat Subfamily of rodents

The blind mole-rats, also known as the fossorial or subterranean mole rats, are a subfamily (Spalacinae) of rodents in the family Spalacidae, found in eastern Europe and western & central Asia. The hystricognath mole-rats of the family Bathyergidae are completely unrelated, but some other forms are also in the family Spalacidae. Zokors, root rats, and bamboo rats are spalacids also sometimes referred to as mole rats.

Nesomyinae Subfamily of rodents

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.

Murinae Subfamily of rodents

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.

Blesmol Family of rodents

The blesmols, also known as mole-rats, or African mole-rats, are burrowing rodents of the family Bathyergidae. They represent a distinct evolution of a subterranean life among rodents much like the pocket gophers of North America, the tuco-tucos in South America, or the Spalacidae from Eurasia.

Middle East blind mole-rat Species of mammal

The Middle East blind mole-rat or Palestine mole-rat is a species of rodent in the family Spalacidae.

<i>Nannospalax</i> Genus of rodents

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, alongside Spalax. Members of this genus are also known as small-bodied mole-rats. As with members of the genus Spalax, they are completely blind, with their eyes being entirely covered by skin.

Lesser blind mole-rat Species of rodent

The lesser blind mole-rat is a species of rodent in the family Spalacidae. It is found in Albania, Bosnia and Herzegovina, Bulgaria, Greece, Hungary, North Macedonia, Romania, Serbia, Montenegro, Turkey and Ukraine.

Petromyscus is a genus of rodent in the family Nesomyidae. It is so distinct from other rodents that it is placed as the only genus in subfamily Petromyscinae. In previous classifications, Delanymys brooksi has also been placed in the subfamily. They are found in southwestern Africa. These animals have a sharp lower point to their V-shaped infraorbital canal. Their molars are intermediate between the ancestral cricetid style tooth and the dendromurine style tooth.

Northeast African mole-rat Species of rodent

The northeast African mole-rat 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 savanna, high-altitude shrubland and grassland. It lives a solitary existence underground and produces a small litter of pups twice a year, in the two rainy seasons. Some taxonomic authorities lump this species, along with a number of others in the genus, in which case the English name East African mole-rat is used.

References

  1. Corbet, Gordon (1984). Macdonald, D. (ed.). The Encyclopedia of Mammals . New York: Facts on File. pp.  666–671. ISBN   0-87196-871-1.
  2. Norris, R.W.; et al. (2004). "The phylogenetic position of the zokors (Myospalacinae) and comments on the families of muroids (Rodentia)". Molecular Phylogenetics and Evolution. 31 (3): 972–978. doi:10.1016/j.ympev.2003.10.020. PMID   15120394.