Late Miocene continental birds from the Cerro Azul Formation in the Pampean region (central-southern Argentina)

Abstract

Cenizo, M.M., Tambussi, C.P. & Montalvo, C.I., iFirst Article. Late Miocene continental birds from the Cerro Azul Formation in the Pampean region (central-southern Argentina). Alcheringa, 1–22. ISSN 0311-5518.

The oldest known birds from the Cerro Azul Formation are described, including the oldest records for the genera Eudromia and Nothura (Tinamidae), Milvago (Falconidae), Pterocnemia (Rheidae) and an undetermined Tyrannidae. The first remains of Phorusrhacidae for this formation are reported and a specimen previously referred to the giant teratorn Argentavis magnificens is reassigned to this family. We outline and update the current knowledge of the groups studied herein. The palaeornithological record from the Cerro Azul Formation is congruent with palaeoenvironmental inferences previously drawn from mammalian assemblages recovered from this unit, which point to the existence of open environments, possibly xerophyllous shrubby steppes, perhaps with some trees. These records are the first indications of a typically Pampean bird fauna at the end of the late Miocene in central-southern Argentina.

Key words:

• Rheidae
• Tinamidae
• Falconidae
• Tyrannidae
• Phorusrhacidae
• Teratornithidae
• Huayquerian

Acknowledgements

This work was partially funded by Project grants from Facultad de Ciencias Exactas y Naturales de la Universidad Nacional de La Pampa. The authors thank K.E. Campbell for sending photographs of the materials referred to A. magnificens deposited at Instituto Miguel Lillo, M.A. Zárate for the critical revision of the section on geological aspects, E.P. Tonni for providing photographs of T. merriami, F. Agnolin and F. Novas for collecting part of the materials studied here and graciously permitting their study.