Early Miocene fossil localities in Africa have produced abundant and diverse mammalian faunas, including, in particular, the remains of rodents.  The vast majority of the fossil rodents are of larger size, i.e., larger than a house mouse.  Smaller rodents are more poorly known, although they were likely an important part of the fossil fauna, based on their abundance in older sites and in the modern fauna.  The Bukwa locality of Uganda is one of the older early Miocene sites; it is dated at about 22 Ma.  The fauna includes many different kinds of mammals, as well as fossil plants, invertebrates, fishes, reptiles, and birds.  Significant among the mammals are the remains of small rodents and a pika tooth.  At least two taxa of rodents are recognized, and one is referred to a new genus and species.  The pika tooth, although not precisely identified, is important because the fossil record of these animals in Uganda is sparse.

Glossary

Early Miocene, period of time from about 23 to 16 million years ago;

Hystricognathi, a group of rodents sharing similar jaw shape and musculature, incisor microstructure, and including the African cane rats, guinea pigs, and all their closest relatives;

Lagomorpha, group including pikas, rabbits, and hares;

Miocene, period of time from about 23 to 5 million years ago;

Ochotonidae, pikas;

Thryonomyoidea, African cane rats and their fossil relatives.