Systematic Affinities of Early Eocene Petrified Woods from Big Sandy Reservoir, Southwestern Wyoming

Abstract

Petrified woods from the Eocene Bridger Formation of Big Sandy Reservoir, southwestern Wyoming, were examined to assess their diversity and systematic affinities. They are assigned to Palmoxylon macginitiei Tidwell, Simper, & Medlyn (Arecaceae), Edenoxylon parviareolatum Kruse (Anacardiaceae), Laurinoxylon stichkai sp. nov. (Lauraceae), Wilsonoxylon edenense gen. et sp. nov. (Canellaceae), and one unnamed dicotyledonous species of uncertain familial affinity. Edenoxylon and Palmoxylon are represented by multiple samples and appear to have been dominant in the local vegetation at the time of deposition. Although the floristic diversity from this locality is low, the affinities of these plants are consistent with other evidence that the climate in the late Early Eocene of this region was subtropical, in contrast with the present arid, temperate conditions.