Members of this remarkable family do not have a wide geographic distribution. They are most numerous and diverse on the island of Madagascar, but a few species are also found in western central Africa. Tenrecs have radiated such that they include species that resemble, both morphologically and ecologically, widely diverse mammals including hedgehogs, shrews, opossums, mice and even otters; and members of the family occupy a diverse collection of habitats, including aquatic, arboreal, terrestrial and fossorial. Currently, we recognize 10 genera of extant tenrecids and 24 species. These are divided into three subfamilies, the Tenrecinae and Oryzoryctinae (both confined to Madagascar) and the Potamogalinae (west-central Africa).
Tenrecs lack jugals, and their zygomatic arches are incomplete. Their tympanic bones are annular, and the squamosal contributes to the roof of the tympanic cavity. The dental formula of tenrecs varies consirably among species, reflecting the diversity of the group: 2-3/2-3, 1/1, 2-3/2-3, 2-4/2-3 = 32-40. The upper molars are zalambdodont, except in the African otter shrews (Potamogalinae), in which they are dilambdodont. The urogenital and anal apertures are included in a cloaca, and the eyes are small. Many tenrecs do not maintain a constant body temperature, but rather let their bodies cool down while they are at rest. At least one species hibernates. Curiously, male tenrecids lack a scrotum and the testes remain within the body cavity.
Members of the large subfamily Tenrecinae are relatively large (up to the size of a cat) and highly variable in body form. All have spines, which are barbed and detachable in some forms and controlled by a well-developed muscle called the panniculus carnosus. Tenrecines are mostly nocturnal and mostly omnivorous. One genus, Hemicentetes, uses its quills to produce sounds that are important in commnication. The Oryzoryctinae are small. Like the Tenrecinae, this subfamily is contains a number of genera and species. They lack spines. Most are shrew-like or mole-like, but one species, in the genus Limnogale, is aquatic. Some are highly fossorial. The Potamogalinae is made up of three species, all aquatic forms called otter-shrews. Potamogale is large, around 600 mm in length and 1 kg in weight, and much modified for aquatic life. Potamogalines probably represent an early branch of the family.
The fossil record of tenrecids is relatively poor. The oldest known fossils are from the Miocene in East Africa and the Pleistocene in Madagascar, but the group is certainly considerably older.
 tenrec |
Family Erinaceidae Family Talpidae Family Solenodontidae Family Tenrecidae Family Chrysochloridae Family Soricidae<<<<<<<>>>>>>> ARTIODACTYLA CARNIVORA CETACEA CHIROPTERA DASYUROMORPHIA DERMOPTERA DIDELPHIMORPHI DIPROTODONTIA HYRACOIDEA INSECTIVORA LAGOMORPHA MACROSCELIDEA MICROBIOTHERIA MONOTREMATA NOTORYCTEMORPHIA PAUCITUBERCULATA PERAMELEMORPHIA PERISSODACTYLA PHOLIDOTA PRIMATES PROBOSCIDEA RODENTIA SCANDENTIA SIRENIA TUBULIDENTATA XENARTHRA
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