Fossil leaves, fruits and seeds of the Late Eocene Teater Road flora near Post, Oregon, USA
Abstract
The Teater Road flora, from a small outcrop of lacustrine shale exposed in Late Eocene sediments of the John Day Formation near Post, Oregon, USA, is presented based on abundant, well-preserved leaf and fruit impressions. We recognize 48 genera or morphotypes of leaves and 58 of reproductive structures, with the most abundant representatives including the aquatic fern, Salvinia, and a variety of angiosperms including Ulmaceae, Fagaceae, Betulaceae, Malvaceae, Simaroubaceae and Sapindaceae (Koelreuteria, Acer spp., Dipteronia). The Teater Road flora represents a diverse mixed mesophytic assemblage of interest for comparison with other Late Eocene floras of western North America and with the nearby Oligocene Gray Ranch flora. Analyses of foliar physiognomy give estimates of mean annual temperature of ca. 10.4 °C and mean annual precipitation of ca. 71 cm per year.