PLIO-PLEISTOCENE FOSSIL MAMMALIAN MICROFAUNA OF SOUTHERN AFRICA- A PRELIMINARY REPORT INCLUDING DESCRIPTION OF TWO NEW FOSSIL

Analyses are presented of the mammalian component of rich microfaunal fossil breccia collections mainly of owl pellet origin from the Transvaal Plio-Pleistocene australopithecine sites Kromdraai, Sterkfontein and Makapansgat Limeworks, with briefer references to Swartkrans, Langebaanweg and the Makapansgat Cave of Hearths. Identification of rodent incisors has proved useful in showing Cryptomys robertsi to be a distinct extinct species occurring with C. hottentotus, and in indicating, thliough the common possession of doubly ridged incisors, a relationship between Mystromys, the Criceto-myidae and certain fossil Cricet~dontidae. The fossil assemblages are generally similar to modern ones but elephant shrews (several species) and dormice are relatively com-moner, and the once dominant cricetid Mystromys has declined in favour of the murid Mastomys. Two genera, Crocidura and Saccostomus are absent from the older fossil sites, appearing only in the more recent Cave of Hearths, while on the other hand there are certain lineages now extinct. Of these Mystromys darti Lavocat has been rediscovered in abundance in in situ Rodent Corner breccia at Makapansgat, yet it is totally absent from other parts of the Limeworks deposit, suggesting a more complex stratigraphy than pre-viously realised. It is referred to a new genus, Stenodontomys, with a second species from Langebaanweg. Another extinct cricetid previously known under a manuscript name as "Mystromys cookei " , common to Makapansgat, Taung and the Krugersdorp district sites, is formally described for the first time also under a new generic name, Proodontomys