Biostratigraphy: Foraminifera, Palynoflora and Ostracods of the Rhaetian of Bac Grillera (Western Spanish Pyrenees)

A marine sequence of Rhaetian age (Upper Triassic) has been identified in the Spanish Western Pyrenees with the help of foraminifera and palynology. The foraminifera, characteristic of the Alpine realm, are essentially represented by the species Aulotortus friedli and Gandinella falsofriedli. The genus Triasina has not been observed. Thus, this outcrop belongs to the Gandinella falsofriedli zone, i.e. the lower subdivision of the Rhaetian s.l., corresponding roughly to the Sevatian. Ostracodes are not age-diagnostic but bring valuable palaeoecological information. A Rhaetian age is confirmed by the presence of the palynomorphs Corollina meyeriana, Rhaetipollis germanicus, Granuloperculatipollis rudis and the dinoflagellate cysts Rhaetogonyaulax rhaetica and Dapcodinium priscum. Data on the systematics of Aulotortus friedli and Gandinella falsofriedli are given. The palaeogeographic importance of this outcrop is emphasized. © 1990.