A new ichnosite and ichnogenus from the Lower Cretaceous Rio do Peixe Basin, Brazil, with novel insights into the evolution of Titanosauriformes

ABSTRACT

Sauropods were a successful group of herbivorous dinosaurs that colonised all continents throughout the Mesozoic. At first glance, the organisms in this group present a conservative shape of quadrupedal animals with elongated necks and tails. However, there was great diversification in the morphology of sauropods, which is still poorly understood in detail, especially during the Early Cretaceous. In this study, we describe a new ichnosite dated from the earliest stages of the Cretaceous of Brazil. The site includes a well-preserved trackway of a large sauropod dinosaur, with manus and pes prints, as well as tracks of theropods and indeterminate tetrapods. The sauropod trackway shows a unique set of characteristics that allowed the erection of a new ichnogenus and ichnospecies, Sousatitanosauripus robsoni igen. nov. et isp. nov. The probable trackmaker was a Titanosauriformes with a mosaic of basal and advanced features, bringing new insights into the diversity and evolution of the group.

KEYWORDS:

• Dinosauria
• Ichnology
• Sauropoda
• Titanosauria
• Sousa Formation

Acknowledgments

We would like to thank Rubens Mota Porfirio, Ana Paula de Assis Silva, José Italo da Silva, Júlia Ellen de Lima Nunes and Michael Vandesteen Silva Souto for discovering the site and for promptly informing us about it; Virgínia Silva Maciel for her valuable help in fieldwork; Arthur Ferreira Sampaio for capturing drone images; Leonardo Troiano and Heloísa B. dos Santos for enabling the loan of the drone; Tibério Felismino de Araújo for his friendship and constant support of our work in the Sousa region; Pedro V. Buck and Marcelo A. Fernandes for their helpful insights on an earlier version of this work; and especially the Braga family, owners of the Sítio Feijão, who kindly welcomed us and allowed us to work there, and in memorian of our friend Robson Araújo Marques the forever guardian of Sousa’s Dinosaur Valley. We also would also like to thank Agisoft for providing a software key for scientific use, and the Postgraduate Program in Geodynamics and Geophysics (PPGG-UFRN) for providing the conditions for developing this work. Finally, we are thankful to the editor, Jens Lallensack and anonymous reviewer for their time and suggestions which significantly helped to improve this work.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/08912963.2024.2385613.

Disclosure statement

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

Additional information

Funding

Z.T.G. received financial support from the National Council for Scientific and Technological Development [CNPq-130467/2023-5], R.F.E. received financial support from the Coordination of Superior Level Staff Improvement [CAPES-88887.929148/2023-00], and T.A. received financial support from Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico [FUNCAP/FPD-0213-00295.01.01/23].