Researchers at the Department of Geology at the UAB, in collaboration with the Catalan Institute of Palaeontology, have systematized the data from 29 sites of bones, footprints and eggs of dinosaurs in the Catalan Pyrenees, one of the best areas in the world to study precisely the time that these animals became extinct. The research, published in the prestigious journal "Palaeogeography, Palaeoclimatology, Palaeoecology", confirms that the diversity of dinosaur species was very large just before the time of termination. This finding refutes some scientific hypotheses which argue that the catastrophe that finally ended the dinosaurs was only the end point of a more gradual process of extinction. In addition, researchers have discovered the unexpected presence of a group of Asian dinosaurs that arrived only one million years before extinction.