Contributions à la Paléontologie du Miocène Moyen continental du Bassin du Tage. I - Quelques mollusques - Pero Filho, Póvoa de Santarém, Sítio do Mirante

Abstract

Key words: Continental mollusks - ecology - middle Miocene - Tagus'basin Some land and freshwater mollusks (Gastropoda, Pelecypoda) from three middle Miocene localities: Pero Filho, Povoa de Santarem, Sítio do Mirante, all in Ribatejo province, Portugal, are summarily studied. On a systematical viewpoint it has been shown (see also Tableau): - the presence of the genus Janulus, whose species only survive now at Madeira and Canary's islands; - the presence of "Helix" cotteri that may indeed belong in the genus Megalotachea, common in western Europe since "Helvetian" to Messinian times; - Limax, Testacella, Acroloxus and Pseudamnicola are quoted for the first time in portuguese tertiary formations; Ferrisia has been identified for the first time in Iberian Peninsule; - the presence of other forms previously quoted by ANTUNES & ZBYSZEWSKI (1973), is confirmed: Bithynia, Theodoxus. Pisidium. Such faunules are compatible with a middle Miocene age. On a paleobiogeographical viewpoint, some forms suggest mediterranean affinities. . Fossil associations do correspond ecologically to either palustrine or stagnant, calm and shallow water conditions (Sítio do Mirante, and essentially also Povoa de Santarem), or to fluviatile conditions (Pero Filho).