Fossil palm beetles refine upland winter temperatures in the Early Eocene Climatic Optimum

作者：Archibald S Bruce^*; Morse Geoffrey E; Greenwood David R; Mathewes Rolf W

来源：Proceedings of the National Academy of Sciences of the United States of America, 2014, 111(22): 8095-8100.

DOI：10.1073/pnas.1323269111

• palm bruchines
• paleoclimate
• Okanagan Highlands
• palm pollen

Eocene climate and associated biotic patterns provide an analog system to understand their modern interactions. The relationship between mean annual temperatures and winter temperatures-temperature seasonality-may be an important factor in this dynamic. Fossils of frost-intolerant palms imply low Eocene temperature seasonality into high latitudes, constraining average winter temperatures there to %26gt;8 degrees C. However, their presence in a paleo-community may be obscured by taphonomic and identification factors for macrofossils and pollen. We circumvented these problems by establishing the presence of obligate palm-feeding beetles (Chrysomelidae: Pachymerina) at three localities (a fourth, tentatively) in microthermal to lower mesothermal Early Eocene upland communities in Washington and British Columbia. This provides support for warmer winter Eocene climates extending northward into cooler Canadian uplands.

• 出版日期2014-6-3