Patarroyo, German D. Kochhann, Karlos G. D. Guerra, Rodrigo M. Alegret, Laia Ceolin, Daiane Torres, José M. Maastrichtian microfossils of the Shallow Marine Umir Formation, Northeastern Colombia Ameghiniana 10.5710/AMGH.02.03.2023.3525 2023 2023