Bivalves (Mollusca) from the Coniacian-Santonian Anguille Formation from Cap Esterias, Northern Gabon, with notes on paleoecology and paleobiogeography

The Aguille Formation (Coniacian-Santonian) of North of Gabonese coastal basin has been analysed from the ‘Cap Esterias’ section. Palaeoecologic and paleogeographic aspects of the bivalves were taken into account. Twelve bivalve species representing 9 genera have been identified from ‘Cap Esterias’ section. Among these Acanthocardia cf. denticula (Baily, 1855), Aphrodina dutrugei (Coquand, 1862) and Protocardia cf. pauli (Coquand, 1862) are found for the first time in the ‘Cap Esterias’ region. A large part (66.67%) of the identified bivalve species occur over a wide geographical area: from Brazil to Central Africa, eastern Mediterranean region, Madagascar, Nigeria, northwestern Africa, South Africa, southern India and southern Europe. The fauna is composed only of suspension-feeders indicating that food resources were dominantly in suspension. The assemblage of bivalves is dominated by shallow burrowing infaunal bivalves and indicates the existence of an unstable and soft substrate. This assemblage can be regarded as parautochthonous.