Baumgartner and Peppe, in review, Palaeogeography, Palaeoclimatology, Palaeoecology 1 This is a preprint of a manuscript submitted to Palaeogeography, Palaeoclimatology, 2 Palaeoecology 3 4 5 Paleoenvironmental changes in the Hiwegi Formation (lower Miocene) of Rusinga Island, 6 Lake Victoria, Kenya 7 8 Aly Baumgartner*a and Daniel J. Peppea 9 a Terrestrial Paleoclimate Research Group, Department of Geosciences, Baylor University, 10 Waco, TX, USA 11 1 Baumgartner and Peppe, in review, Palaeogeography, Palaeoclimatology, Palaeoecology 12 Paleoenvironmental changes in the Hiwegi Formation (lower Miocene) of 13 Rusinga Island, Lake Victoria, Kenya 14 Aly Baumgartner*a and Daniel J. Peppea 15 a Terrestrial Paleoclimate Research Group, Department of Geosciences, Baylor University, 16 Waco, TX, USA 17 Correspondence: 18 Aly Baumgartner 19
[email protected] 20 21 Abstract 22 The Early Miocene of Rusinga Island (Lake Victoria, Kenya) is best known for its vertebrate 23 fossil assemblage—particularly of early hominoids and catarrhines—but the multiple 24 stratigraphic intervals with well-preserved fossil leaves have received much less attention. The 25 Hiwegi Formation has three fossil leaf-rich intervals: Kiahera Hill, R5, and R3. Here, we made 26 new fossil collections from Kiahera Hill and R3 and compared these floras to previous work 27 from R5 as well as modern African floras. The Kiahera Hill flora was most similar to a modern 28 tropical rainforest or tropical seasonal forest and was a warm and wet, closed forest. This was 29 followed by a relatively dry and open environment at R5, and R3, which was most similar to a 30 modern tropical seasonal forest, was a warm and wet spatially heterogenous forest.