 The study presents an integrated approach using magnetostratigraphy, larger benthic foraminifera and calcareous nanofossil biostratigraphy to improve the knowledge of larger benthic foraminifera distribution in the Esera Valley section. The results show that the SBZ12 slash SBZ13 boundary occurs in the lower Lutien, younger than previously believed, and the Eprision slash Lutien boundary occurs in SBZ12. This article was authored by Adriana Rodriguez Pinto, Josep Sarriquil, Gailen Bernayla, and others.