; order Rodentia, suborder Hystricomorpha)
A monospecific family (Petromys typicus) of squirrel-like rodents, which have ribs that can be moved in such a way as to allow the animal to compress its body dorsoventrally. The ears are short, the tail has a terminal tuft, the limbs are short, and the first digit is very short in the hind limbs and vestigial in the fore limbs. The animals shelter in crevices in rocks. They are found only in south-western Africa.
Subjects: Zoology and Animal Sciences.