Late Eocene penguins from West Antarctica: systematics and biostratigraphy

TAMBUSSI, C., C. ACOSTA HOSPITALECHE, M. REGUERO & S. MARENSI

JOURNAL OF THE GEOLOGICAL SOCIETY

GEOLOGICAL SOC PUBL HOUSE

Año: 2006 p. 1 - 28

0016-7649

Abstract: Penguins are by far the dominant group of marine vertebrates in the Eocene La Meseta Formation (Seymour Island, Antarctica). We analyze the penguin fauna recovered there from systematic and biostratigraphic points of view. We have added two new species (Tonniornis mesetaensis and T. minimum) and we have defined a biostratigraphic unit, the Anthropornis nordenskjoeldi Biozone. This interval of strata, easily distinguishable by the numerous occurrence of penguin bones and the phosphatic brachiopod Lingula, is located nearly 30-35 metres below the top of the 145 metres thick Submeseta Allomember. The highest morphological and taxonomic penguin diversity living simpatrically (organism that live simultaneously in the same place), including giant and tiny species, is documented in this interval. Fossil penguins bones studied in this paper recovered from rocks interpreted as shallow marine deposits were accumulated between 36.13 and 34.2 Ma (late Late Eocene).