Bioerosion trace fossils on bones of the Cretaceous South American theropod Buitreraptor gonzalezorum Makovicky, Apesteguía and Agnolín, 2005 (Deinonychosauria)

Abstract

The ichnological record provides valuable information on the lifestyle, behaviour, and other palaeobiological and palaeoecological aspects of the biota. Here, we describe an interesting case of bioerosion trace fossils in bones of Buitreraptor gonzalezorum Makovicky, Apesteguía and Agnolín, 2005, a deinonychosaurian theropod from the fossiliferous locality of La Buitrera, Río Negro, Patagonia, Argentina. The trace fossils are morphologically diverse and preserved in a great percentage of the skeleton, including the jaw, vertebrae and limbs. Four main groups of trace fossils have been informally named as Parallel-Edge Furrows, Overlapped Grooves, Punctures and Lined. Parallel-Edge Furrows are in turn subdivided into four subgroups: isolated furrows, parallel pairs, opposed pairs and a combination of parallel and opposed pairs. The bioerosion trace fossils were probably generated by scavenging activities, and the semi-articulated preservation of the skeleton and the small size of each individual trace indicate small-sized tracemakers. Mammals are the main candidates although some traces may have been generated by crocodyliforms and insects such as dermestids and termites. This evidence provides additional information about palaeoenvironmental conditions, taphonomic processes, taxonomic diversity and ecological relationships that characterised this part of northern Patagonia at Early Cretaceous times.

Keywords::

• ichnological evidence in bones
• scavenging
• Buitreraptor gonzalezorum
• Patagonia
• Cretaceous

Acknowledgements

We thank Carlos Muñoz and Ignacio Cerda, from the Museo ‘Carlos Ameghino’, Cipolletti, Río Negro, for providing access to its collection. Comments made by Sebastián Apesteguía, Leandro Gaetano and Andrea Arcucci have been much appreciated. We also thank Jorge González for allowing us to use some of his artwork. The assistance of Mariana Pascual (Área Lenguas Extranjeras, Facultad de Ciencias Humanas, Universidad Nacional de San Luis) was very useful in the grammatical revision of the text. Two anonymous reviewers and Gareth Dyke provided valuable comments that greatly improved the final outcome of the paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by funds of CONICET [grant number PIP 0053].