The paleontological record of a set of upper Tortonian outcrops nearby Las Pajanosas, north of Seville, has
been studied. The most complete series of 15 metres of thickness, unconformed over upper Devonian
metamorphic rocks, is divided in two sedimentary parts. 60 macrofaunal species have been identified.
Bivalves group is the most abundant with 37 species, specially pectinids with 14 species. This outcrop
presents the most diversity of pectinids in the Tortonian sections of the Guadalquivir Basin. The fossil
content, distribution, taphonomy signature and sedimentological context, suggest a transgressive process
over the paleorelief, with progressive deepening of the paleoenvironments in a global eustatic rising settin