Add to ORKGThe study of the ammonite fauna of the Lower to Early Upper Albian formations allow a major revision of the biostratigraphic frame of Northern and Central Peru. A new subdivision in ammonites zones, subzones and bio-horizons terms is proposed. The Lower Albian is represented by the Nicholsoni Biozone (subdivided into the umbilicostatus and nicholsoni biohorizons, followed by an Interval Subzone) and by the Raimondii Biozone (carved in three subzones: Haasi, Raimondii - itself divided into the ebrayi and alternum biohorizons and Mathewsi, including the pseudolyelli biohorizon). The Middle Albian is characterized by the Carbonarium Biozone, carved in the Ulrichi and Carbonarium Subzones. The base of the Upper Albian is represented by the Cris...