Re-evaluation of the fossil penguin Palaeeudyptes gunnari from the Eocene Leticia Formation, Argentina: additional material, systematics and palaeobiology

Abstract

Acosta Hospitaleche, C. & Olivero, E., April 2016. Re-evaluation of the fossil penguin Palaeeudyptes gunnari from the Eocene Leticia Formation, Argentina: additional material, systematics and palaeobiology. Alcheringa 40, xx–xx. ISSN 0311-5518

Eocene penguins are known mostly from Antarctic specimens. A previously documented partial skeleton consisting of a pelvis, femur, tibiotarsus and fibula, from the middle Eocene Leticia Formation, Tierra del Fuego Province, Argentina, has been prepared and re-described. Re-analysis favours assignment to Palaeeudyptes gunnari, a species widely recorded in the Eocene of Antarctica. A new isolated coracoid belonging to an indeterminate species reveals new information about diving kinematics and swimming abilities. Palaeobiological attributes and morphology of the fossils indicate that both specimens belonged to large penguins with poor diving capability and wing propulsion systems similar to those of extant taxa. These penguin remains are the only vertebrate fossils thus far recorded from the Leticia Formation, and provide important insights into the relationships of South American and Antarctic penguins during the Paleogene. The presence of Palaeeudyptes in Argentina supports an Eocene connection between the South American and Antarctic penguin faunas.

Carolina Acosta Hospitaleche [[email protected]], CONICET. División Paleontología Vertebrados, Museo de La Plata Paseo del Bosque s/n, 1900 La Plata, Facultad de Ciencias Naturales y Museo, UNLP, Argentina; Eduardo Olivero [[email protected]], CONICET. Centro Austral de Investigaciones Científicas (CADIC-CONICET), B. Houssay 200, 9410 Ushuaia, Tierra del Fuego, Argentina.

Key words:

• Fossil penguin
• Palaeeudyptes gunnari
• Eocene
• South America
• Antarctica

Acknowledgements

We thank the Agencia Nacional de Promoción Científica y Tecnológica (PICTO 0114, PICTO 0093, PICT 0284), Consejo Nacional de Investigaciones Científicas y Técnicas (PIP 114-0341, PIP 0017) and Universidad Nacional de La Plata, for partial financial support. The reviewers and editors contributed with helpful suggestions. Dra. Cecilia Morgan improved the English grammar.