Eocene Antarctica:a window into the earliest history of modern whales

作者：Mónica RBUONO,REwan FORDYCE,Felix GMARX,Marta SFERNáNDEZ,Marcelo AREGUERO

摘要：The Eocene–Oligocene Southern Ocean is thought to have played a major role in cetacean evolution.Yet,fossils from its heart—Antarctica—are rare,and come almost exclusively from the Eocene La Meseta and Submeseta formations of Marambio(Seymour)Island.Here,we provide a summary and update of this crucial fossil assemblage,and discuss its relevance in the broader context of cetacean evolution.To date,Eocene specimens from Antarctica include basilosaurids,a group of archaic stem cetaceans that had already fully adapted to life in water;and the archaic toothed mysticete Llanocetus,the second oldest crown cetacean on record(ca.34 Ma).This Eocene co-occurrence of stem and crown cetaceans is highly unusual,and otherwise only observed in Peru.Though related,at least some of the Antarctic species appear to be different from,and notably larger than their Peruvian counterparts,suggesting an early differentiation of the high latitude cetacean fauna.

发文机构：Instituto Patagónico de Geología y Paleontología Department of Geology Departments of Paleobiology and Vertebrate Zoology Directorate of Earth and History of Life Department of Geology School of Biological Sciences Palaeontology CONICET-División Paleontología Vertebrados CONICET-División Paleontología de Vertebrados Instituto Antártico Argentino（Dirección Nacional del Antártico）

关键词：Marambio(Seymour)ISLANDBasilosauridaeMysticetievolution

分类号： P53[天文地球—古生物学与地层学][天文地球—地质学]