Key words: Dinosauria, Dromaeosauridae, Abelisauridae, theropod diversity, paleobiogeography, Campanian, Maastrichtian, Gondwana.

Federico Fanti fanti@geomin.unibo.it, Department of Earth and Geoenvironmental Sciences, University of Bologna, Via Zamboni 67, I-40127 Bologna, Italy; François Therrien francois.therrien@gov.ab.ca, Royal Tyrrell Museum of Palaeontology, P.O. Box 7500, Drumheller, Alberta, Canada, T0J 0Y0.