Abstract
Late Early Pliocene palaeo-vegetation based on the plant macrofossil assemblages of fossil elephant skull Stegodon miensis containing layer founded from the middle part of the Tsubusagawa Formation distributed in Hirayama area, Ajimu Town, Usa City, Oita Prefecture reconstructed.
There was a swamp zone where aquatic plants Potamogeton and Trapa are growing, and an open wetland spreading over the genera Carex, Cyperus, and Schoenoplectiella was grown. There also exist sunny and dry land area, where the genera Persicaria, Boehmeria, Lamium, and Angelica grow. Evergreen coniferous Cryptomeria, evergreen broad-leaved tree Cinnamomum, deciduous broad-leaved tree Litsea, Cornus, and Betulaceae have been grown around sedimentary areas.