Vertebrate Tracksites in the Middle Jurassic-Upper Cretaceous of South Tunisia

Abstract

Four vertebrate tracksites from the Middle Jurassic and Upper Cretaceous in the Tataouine basin of southern Tunisia are described. Approximately 130 tridactyl footprints distributed over an area of 200 square meters, preserved on Callovian beds exposed at the Beni Ghedir site, represent the oldest evidence of a dinosaur fauna in Tunisia. In addition, three tracksites—Chenini, Ksar Ayaat, and Jebel Boulouha—have been discovered in the Cretaceous beds of the upper Continental Intercalaire, previously considered as a strictly marine depositional sequence. In addition to dinosaur tracks, the Chenini tracksite (late Albian) includes poorly preserved crocodilian tracks, and footprints assigned to a pleurodiran turtle have been recovered at the Ksar Ayaat locality (early Cenomanian). The Jebel Boulouha tracksite is dominated by well-preserved tridactyl tracks referred to small-sized theropods. Depositional settings of each tracksite have been defined on stratigraphic and sedimentologic data, and tracks were ascribed to different ichnocoenoses in relation to their paleoenvironments. This new and differentiated track record gives important information on how the fossil vertebrate fauna changed in southern Tunisia during mid-Jurassic to mid-Cretaceous times. These data provide a unique and useful census of tetrapod associations along the southern margin of the peri-Mediterranean area.

Keywords:

• Ichnology
• Paleoecology
• Vertebrate tracks
• Theropod tracks
• Ichnocoenoses
• Tunisia

ACKNOWLEDGMENTS

The authors are grateful to H. Aljane (Office National des Mines, Tunis, Tunisia), M. Avanzini (Museo Tridentino di Scienze Naturali, Italy), A. R. Fiorillo (Museum of Nature & Sciences, Dallas, Texas, USA) and M. Polcyn and T. Adams (Visualization Laboratory at the Southern Methodist University). We also thank A. and G. Bacchetta, F. Scarelli, G. Rivalta and F. Franchi for their support in the field. This research was conducted in the context of the senior author's Ph.D. (Department of Earth and Geoenvironmental Sciences, University of Bologna, Italy) and was financially supported by Fondazione Alma Mater, Prof. Giovanni Gabbianelli, and the Museo Geologico Giovanni Capellini (Bologna, Italy).