Palaeoecology of Miocene sites in Western Kenya

Abstract

The palaeoecology of the Miocene sites of Western Kenya is reviewed. Because fossil floras are usually not preserved the evidence on palaeoecology is mostly obtained from the fossil faunas. These are analysed by five methods: analysis of indicator species, habitat spectra, taxonomic habitat indices, ecological diversity analyses, and socio-ecology. The results indicate that the Songhor fauna was probably derived from forest habitat close to the place of deposition. In the Koru area the faunas from the Legetet Formation and the Chamtwara Member of the Kapurtay Agglomerates were similarly derived from forest habitats, but the Koru Formation fauna indicates more open conditions. The Rusinga and Karungu faunas have not been analysed in detail, and as they are associated with flood plain sedimentary environments it is probable that they are biased and not representative of any on living community, although there is some evidence also for forest conditions. This is supported by evidence from the fossil flora of Rusinga. Two Middle Miocene faunas from Maboko and Fort Ternan both indicate the presence of woodland or woodland savanna habitats, suggesting a major ecological shift from the faunal habitat of the Early Miocene.