Biomechanical skull performance in the meiolaniid Niolamia argentina (Testudinata: Meiolaniidae) using Finite Element Analysis

ABSTRACT

The use of horns and frills for sexual display and attack has been proposed and demonstrated in extinct taxa on several occasions, with the ceratopsian dinosaurs as the most iconic example. Niolamia argentina is a large meiolaniid turtle from Patagonia, characterized by the presence of extensive frills and massive horns in the skull. Here, Finite Element Analysis (FEA) is applied in the only known adult skull of N. argentina to assess the cranial performance simulating defensive/aggressive movements. We tested five different scenarios: (1) hitting with the snout, (2) hitting with the forehead, (3) struggling with the notch between the frill and the horn, (4) stabbing with lateral horns, and (5) caudal torsion of the frills, the last two being the most damaging and stressful scenarios. Together with the lack of skull features related to head-hitting/fighting, we find that, although the cranial structures of Niolamia argentina studied here may indicate a priori that they were for engaging in combat between males, hitting each other with the caudal frills and trying to stab each other may represent highly stressful scenarios. In this sense, we propose that the presence of frills and horns in N. argentina seems to be more suitable for sexual display than for combat behavior.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

ACKNOWLEDGMENTS

We would like to thank M. Reguero and E. Tonni (Museo de La Plata, La Plata, Argentina) and Y. Y. Zhen and I. Percival (Geological Survey of New South Wales ex Mining Museum, Australia) for granting access to the specimens here studied. The Instituto del Este de Chubut (Trelew, Argentina) is thanked for the CT scan of Niolamia argentina. S. Poropat (Curtin University, Australia), A. Klinkhamer (University of New England, Australia), and H. Laurendet (University of Sydney Veterinary Teaching Hospital, Australia) are thanked for the CT scan of Meiolania platyceps. Thanks to the editor T. Lyson, and Y. Rollot, G. Ferreira, and an anonymous reviewer for their helpful comments. This work was supported by PICT 2017-1319 and 2021-00294 (FJD); PUE 2016-CONICET–CICTERRA; and PICT 2018-01848 (JS). These grants promote the development and strengthening of the Argentine scientific system resulting in one of the most prestigious in the world. Dismantling the Argentine scientific system is a tragedy for the present and future of the country.

AUTHOR CONTRIBUTIONS

All authors designed the project. J.S and E.V. procured the µCT data. F.J.D. processed the µCT, made the figures, and drafted the manuscript. F.J.D. and M.N.N. performed the analyses. All authors edited, reviewed, and approved the manuscript.

DATA AVAILABILITY STATEMENT

The high-resolution images of thin sections used in this study are available on Morphosource, project: 000612325 at: https://www.morphosource.org/concern/media/000612325

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Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.