Procellariiform remains and a new species from the latest Eocene of Antarctica

Abstract

New remains from the La Meseta (Thanetian – Lutetian) and Submeseta (Lutetian – Rupelian) formations (Seymour Island, Antarctica) are tentatively assigned to Diomedeidae and Procellariidae (Procellariiformes). Based on the fossil record and several analyses that attempt to explain the evolutionary patterns of Diomedeidae, Notoleptos giglii gen. et sp. nov., based on a small tarsometatarsus, was an ancestral form that lived in Antarctica before the rise of large-sized albatrosses. Subsequent environmental cooling since the late Oligocene could have selected against small body size, to the detriment of small-sized albatrosses like Notoleptos, thus favoring large body size and setting the stage for the development of the specialized albatross flight.

ZooBank ID (LSID): urn:lsid:zoobank.org:pub:C8D9C862-1536-4EA3-8A76-70903AA75639

Keywords:

• Small albatross
• Diomedeidae
• phylogeny
• Seymour Island

Acknowledgements

We are grateful to Marcelo Reguero (Museo de La Plata, La Plata, Argentina) for inviting us to Antarctic field trip and for access to the material studied here, Diego Montalti (Museo de La Plata, La Plata, Argentina), and Washington Jones (Museo Nacional de Historia Natural, Montevideo, Uruguay) for access to comparative materials, Nadia Haidr for images for comparative material. Cecilia Morgan and Darin Croft improved the English grammar, Bruno Pianzola took the pictures and Soledad Gouiric-Cavalli helped with the drawings. We would like to thank the two anonymous reviewers of the previous version for their helpful criticisms and comments. We also thank the Instituto Antártico Argentino-Dirección Nacional del Antártico (IAA-DNA) for inviting us to the field, Fuerza Aérea Argentina for logistic support, and the rest of the Heidi Group that participated in field work.