The Scleractinian fauna from the Serravallian of Pessac (North Aquitaine Basin, SW France); paleoecological data.

An abundant fauna of Scleractinian corals has been studied from a Mid Mioce ne (Serravallian) new outcrop in the North Aquitaine Basin (SW France). It consists of more than fifteen taxa, with a noticeable diversification in th e genera Flabellum and Balanophyllia, 10 of these taxa are new in the Mioce ne of the Aquitaine Basin. This is probably the richest assemblage of the F rench Serravallian. The name Flabellum montanaroae nov. nom. is set. Biogeo graphically, the studied locality bears witness to Northern, Atlantic and M editerranean influences. The ahermatypic content of the fauna agrees with t he observed general trends to a gradual disappearance of reefal species and to a cooling in neritic waters during the Mid Miocene along the Northeaste rn Atlantic frontage. In terms of paleoecology, the corals-rich deposit con tains an abundant malacofauna, which indicates an infralittoral, euhaline, and fairly calm environment, with a marry-sandy substrate; this biofacies l ooks like the muddy facies of the modern assemblage SFBC ("Sables Fins Bien Calibres").