The African palm fossil record is limited but the data provide an outline of palm evolution from the Late Cretaceous through the Neogene. Pollen attributed to palms is reported from the Aptian (125–112 Mya), but the earliest unequivocal record in Africa is Campanian (83.5–70.6 Mya). Palms diversified 83.5–65.5 Mya and became widespread, although most records are from the west and north African coasts. Many taxa were shared between Africa and northern South America at that time, but a few were pantropical. Extirpations occurred throughout the Palaeogene, including a notable species turnover and decline at the Eocene–Oligocene boundary (33.9 Mya), a change that resulted in the elimination of nypoid palms from Africa. The Neogene plant macrofossil record is better sampled than the Palaeogene, although few palms are documented. Thus, the low diversity of African palms today is more likely the result of Palaeogene, rather than Neogene extinctions. Newly discovered palm fossils of leaves, petioles and flowers from the Late Oligocene (27–28 Mya) of north‐western Ethiopia document the abundance and dominance of palms in some communities at that time. The fossils represent the earliest records of the extant genera Hyphaene (Coryphoideae) and Eremospatha (Calamoideae). © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society, 2006, 151, 69–81.

Afro-Arabian mammalian communities underwent a marked transition near the Oligocene/Miocene boundary at approximately 24 million years (Myr) ago. Although it is well documented that the endemic paenungulate taxa were replaced by migrants from the Northern Hemisphere, the timing and evolutionary dynamics of this transition have long been a mystery because faunas from about 32 to 24 Myr ago are largely unknown. Here we report a late Oligocene fossil assemblage from Ethiopia, which constrains the migration to postdate 27 Myr ago, and yields new insight into the indigenous faunal dynamics that preceded this event. The fauna is composed of large paenungulate herbivores and reveals not only which earlier taxa persisted into the late Oligocene epoch but also demonstrates that one group, the Proboscidea, underwent a marked diversification. When Eurasian immigrants entered Afro-Arabia, a pattern of winners and losers among the endemics emerged: less diverse taxa such as arsinoitheres became extinct, moderately species-rich groups such as hyracoids continued into the Miocene with reduced diversity, whereas the proboscideans successfully carried their adaptive radiation out of Afro-Arabia and across the world.

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Oligocene (28-27 Ma) leaf fragments displaying morphological affinities with the fern Acrostichum are described from volcanic and fluvio-lacustrine strata near Chilga, west-southwest of Gondar on the northwestern Ethiopian Plateau. The fossils consist of elongate pinnae impressions and compressions, with secondary veins that arise from a midvein, anastomose, and create a characteristic reticulate venation without included free veinlets. Modern Acrostichum has a pantropical distribution associated with mangrove vegetation, but it occasionally occurs in freshwater settings. The Paleogene fossil record shows that Acrostichum usually is preserved in freshwater environments, as it is at Chilga, but elsewhere in Africa it is associated with mangrove taxa. At Chilga, Acrostichum occurs in a waterlogged terrain, as indicated by independent environmental assessment based on paleosol analyses. This fern occupied a greater geographic range than it does today in Africa, having occurred in the past on the Ethiopian Plateau in addition to the coastal areas at tropical latitudes.