Large extinct canids from the Pleistocene of Uruguay: systematic, biogeographic and paleoecological remarks

Abstract

The fossil record of Canidae in South America begins in the Late Pliocene. During the Pleistocene large hypercarnivore canids (Theriodictis, Protocyon, Canis dirus) and also large species of Neotropical foxes (Dusicyon avus) evolved. Most fossil canids were found in Chile, Ecuador, Bolivia, Brazil, Venezuela and Argentina and are scarce or absent in other countries. From Uruguay only fossils referred to Dusicyon gymnocercus, ‘Pseudalopex’ and ‘Canis’ are currently known. We describe new records that belong to large canids from the Sopas Fm. (Late Pleistocene) of Uruguay and discuss their biogeographic and paleoecologic relevance. These specimens are referred to Protocyon troglodytes and D. avus by means of descriptive and multivariate analysis and constitute the first records of these taxa for Uruguay, expanding and completing their distribution in the Late Pleistocene of South America. Both species could have been occupied ‘niches’ not represented by the carnivores previously registered in the Sopas Fm. (Puma concolor, Panthera onca, Lontra longicaudis, etc.) suggesting more complex biotic interactions in the mammalian assemblages than previously assumed. The large hypercarnivorous canid P. troglodytes could hunt medium-large sized mammals, pursuing their prey in packs over long distances, while the medium canid D. avus could prey on small and middle mammals.

Keywords:

• Late Pleistocene
• South America
• large canids

Acknowledgements

M. Trindade (Salto-Uruguay) allowed us to study the fossil material. We would like to thank several Curators who helped during Collection visits: David Flores, Alejandro Kramarz, Marcelo Reguero; Lucas Pomi, Itatí Olivares, M. Trindade, Diego Verzi, Alejandro Dondas, Richard Tedford, John Flynn, Bruce MacFadden, Richard Hulbert, Bill Simpson, Ross MacPhee, Bruce Patterson, Ascanio Rincón, Judy Galkin, Min-Tho Schulenberg, William Stanley, Linda Gordon, Mattherw Carrano, Sumru Arincali, Tom Amorosi, Luciano Prates, Mariano Bonomo, Alfredo Prieto, Guillermo Delia, Amador Rodríguez, Daniel Ibáñez, D. Dias Henriques, Alejandro Salles and José Luis Carrion. We would also like to thank Tom Amorosi for the help and advice given during the visit of one of us (FJP) to the AMNH. This paper is a contribution to CSIC-Project-2009-2011 C 828-102 (M. Ubilla), and UNLP N-336, UNLP N-441, and PICT 38171 (FJP). Thanks to Gareth Dyke for comments and help with the English; to the American Museum of Natural History for travel and visitation grants awarded to one of the authors (FJP); and to Richard Tedford and an anonymous referee for their useful comments and corrections.

Notes

^1. [email protected]

^2. [email protected]

Additional information

Notes on contributors

M. Ubilla

1. 1. [email protected]

D. Perea

2. 2. [email protected]