Canid Coprolites from the Late Pleistocene of Hidalgo, Central Mexico: Importance for the Carnivore Record of North America

ABSTRACT

We present the first reported occurrence of canid coprolites from the late Pleistocene of central Mexico. The sample consists of five associated coprolites recovered from Quaternary deposits that crop out in southeastern Hidalgo, central Mexico. The material shows several of the typical features of canid feces, including elongated cylindrical shape, uncommon and nondistinct constrictions, and one tapered end. The coprolites are similar in size to feces of North American foxes, such as Vulpes macrotis, V. lagopus, V. vulpes, and Urocyon cinereoargenteus; likewise, their size might be comparable to those of the Pleistocene canid Canis cedazoensis. The content of the studied coprolites consists of numerous teeth and bone fragments referable to the pocket gophers Pappogeomys or Cratogeomys. The coprolite content is related to a mostly carnivorous diet comparable to that of C. cedazoensis, wolves (Canis lupus, C. rufus, and C. dirus), and some foxes (V. macrotis and V. velox). As a result, it is proposed that the potential trace maker of the coprolites could be a form similar to a carnivorous fox or a small dog. These trace fossils represent the first indirect evidence of canids in the late Pleistocene of Hidalgo and provide additional information regarding the geographic distribution of the Canidae in temperate areas of North America that now are part of central Mexico during the second half of the Pleistocene.

KEYWORDS:

• Canids
• Coprolites
• Mexico
• Pleistocene

Acknowledgments

We are indebted to the reviewers R. Rodríguez de la Rosa and Spencer G. Lucas for their comments and suggestions that significantly improved the final version of the article. Thanks to Alberto Arenas Flores, of the Laboratorio de Difracción de Rayos X, Área Académica de Ciencias de la Tierra y Materiales, Universidad Autónoma del Estado de Hidalgo, for their help with the mineral composition analysis procedure. At last but not the least, we thank Richard G. Bailey and Ana Lorena Morales García (The University of Sheffield, United Kingdom) for their kind support with the linguistical review. This study is part of the project CONACyT−Ciencia Básica (CB−2009−01, No. 130712): El registro de ungulados terrestres en el Pleistoceno de Hidalgo, Puebla y Tlaxcala, centro de México: Interpretación de hábitos alimentarios y caracterización de paleocomunidades terrestres.