Spalax

Spalax
Temporal range: Early Miocene–Recent
Spalax ehrenbergi
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Rodentia
Superfamily: Muroidea
Family: Spalacidae
Subfamily: Spalacinae
Gray, 1821
Genus: Spalax
Guldenstaedt, 1770
Species

Spalax arenarius
Spalax carmeli
Spalax ehrenbergi
Spalax galili
Spalax giganteus
Spalax golani
Spalax graecus
Spalax judaei
Spalax leucodon
Spalax microphthalmus
Spalax munzuri
Spalax nehringi
Spalax uralensis
Spalax zemni

Synonyms

Nannospalax Palmer, 1903

The genus Spalax contains the blind, fossorial, or subterranean mole rats, which are one of several types of rodents that are called mole rats[1]. The hystricognath mole rats of the family Bathyergidae are completely unrelated, but some other forms are also in the family Spalacidae. Zokors (subfamily Myospalacinae) and root rats and bamboo rats (subfamily Rhizomyinae) are spalacids sometimes referred to as mole rats. Blind mole rats are in the family Spalacidae, but are unique enough to be given a separate subfamily, Spalacinae. Alternate opinions on taxonomy consider the blind mole rats to be the only members of the family Spalacidae and rank other spalacid subfamilies as full families. Other authors group all members of the superfamily Muroidea into a single family, Muridae. The Spalacinae contains two genera and eight species. Some authorities treat all species as belonging to a single genus, Spalax.

Spalax mole rats are truly blind. Their very small eyes are completely covered by a layer of skin. Unlike many other fossorial rodents, Spalax mole rats do not have enlarged front claws and do not appear to use their forearms as a primary digging tool. Digging is almost exclusively conducted using their powerful front teeth, which are separated from the rest of the mouth by a flap of skin. When a Spalax mole rat closes its mouth, its incisors are still on the outside. It has been suggested that blind mole rats may have evolved from spalacids that used their front limbs to dig, because their olecranon process is relatively large relative to the rest of the arm. The olecranon process is a part of the ulna bone where muscles attach, and digging animals tend to have enlarged olecranon processes to provide a lot of surface for their large and powerful muscles to attach.

Because they are completely blind, blind mole rats have been important laboratory animals in tests on how eyes and eye proteins function.

Classification

Subfamily Spalacinae

References

  1. ^ Macdonald, D., ed (2006). The Encyclopedia of Mammals. Oxford: Oxford University Books. p. 203. ISBN 0-87196-871-1.