Paleocene-Eocene warming and biotic response in the epicontinental West Siberian Sea

We present a Paleocene-Eocene (ca. 60-52 Ma) sea-surface temperature record from sediments deposited in the epicontinental West Siberian Sea. TEX86 paleothermometry indicates long-term late Paleocene (similar to 17 degrees C ca. 59 Ma) to early Eocene (26 degrees C at 52 Ma) sea-surface warming, consistent with trends previously observed for the Southern Ocean and deep oceans. Photic zone and seafloor anoxia developed as temperatures rose by 7 degrees C to similar to 27 degrees C during the Paleocene-Eocene Thermal Maximum (PETM). Based on paired palynological and TEX86 data, we suggest that the minimum temperature for the proliferation of Paleocene and early Eocene members of the dinoflagellate family Wetzelielloideae, which includes the PETM marker taxon Apectodinium, was similar to 20 degrees C.