We describe for the first time in the Lago Colhue Huapi Formation (Coniacian-Maastricthian), - Maastricthian), south Central Patagonia, Argentina, continental bioerosion traces on dinosaur remains. Specifically, six different morphotypes, showing also different morphologic patterns, were identified. The preliminary identification of the trace makers include: crocodyliform, possibly a peirosaurid notosuchian (morphotypes A and B), a theropod dinosaur (morphotype C), and the activity of arthropod pupation (morphotype D) and insects such as termites and dermestids (morphotypes E and F). This study increases our knowledge about the biodiversity registered to the moment in the Lago Colhue Huapi Formation and specifically for the "middle section" of this formation, probably Santonian-early - early Maastrichtian in age. These bioerosion traces support a warm climate with periods of semi-aridity or at least drier conditions as it was proposed for this interval of time in this section of the formation.