Annales Societatis Geologorum Poloniae (2018), vol. 88: 223 – 241. doi: https://doi.org/10.14241/asgp.2018.014 TITANOSAUR TRACKWAYS FROM THE LATE CRETACEOUS EL MOLINO FORMATION OF BOLIVIA (CAL ORCK’O, SUCRE) Christian A. MEYER1, Daniel MARTY2 & Matteo BELVEDERE3 1 Department of Environmental Sciences, University of Basel, Bernoullistrasse 32, CH-4056 Basel, Switzerland; e-mail:
[email protected] 2 Museum of Natural History Basel, Augustinergasse 2, CH- 4000 Basel, Switzerland; e-mail:
[email protected] 3 Office de la culture, Paléontologie A16, Hôtel des Halles, P.O. Box 64, CH-2900 Porrentruy 2, Switzerland; e-mail:
[email protected] Meyer, C. A., Marty, D. & Belvedere, M., 2018. Titanosaur trackways from the Late Cretaceous El Mo- lino Formation of Bolivia (Cal Orck’o, Sucre). Annales Societatis Geologorum Poloniae, 88: 223 – 241. Abstract: The Cal Orck’o tracksite is exposed in a quarry wall, approximately 4.4 km NW of Sucre (Department Chuquisaca, Bolivia) in the Altiplano/Cordillera Oriental, in the El Molino Formation (Middle Maastrichtian). Fossiliferous oolitic limestones, associated with large, freshwater stromatolites and nine levels of dinosaur tracks in the El Molino Formation document an open lacustrine environment. The main track-bearing level is almost vertical with a surface area of ~ 65,000 m2. The high-resolution mapping of the site from 1998 to 2015 revealed a total of 12,092 individual dinosaur tracks in 465 trackways. Nine different morphotypes of dinosaur tracks have been documented. Amongst them are several trackways of theropods, orni- thopods, ankylosaurs and sauropods, with the latter group accounting for 26% of the trackways.