A study in hystricomorph rodent relationships: the karyotypes of Thryonomys gregorianns, Pedetes capensis and Hystrix cristata

Karyotypes and G band patterns of Thryonomys gregorianus, Pedetes capensis and Hystrix cristata from Kenya are reported. Both Thryonomys and Pedetes have a diploid number of 40 but differ in the overall pattern of their karyotypes and by the presence of a marker chromosome in Thryonomys. The marker chromosome unites Thryonomys with the ctenodactylids. The karyotype of Hystrix cristata , with a diploid number of 60, bears some resemblance to the African bathyergids and Petromus but none to the erethizontids. The African hystricomorph-hystricognath rodents, with the exception of Pedetes , bear more resemblance to the South American caviomorphs than to any other group of rodents.