Author(s):
Ávila, Sérgio P. 
; Amen, Rui G. ; Azevedo, José M. N. ; Cachão, Mário ; García-Talavera, Francisco
Date: 2002
Persistent ID: http://hdl.handle.net/10400.3/1019
Origin: Repositório da Universidade dos Açores
Subject(s): Pleistocene species; Praia Formosa; Santa Maria Island; Patella ulyssiponensis; Myoforceps arustatus; Eruilin castanea; Lucinella diwricntn; Ensis minor; Fauna Malacológica Marinha
Description
A critical review of the reported Pleistocene species of and Lagoinhas (Santa Maria Island, Azores) is provided, new data increasing the marine molluscan fauna to 95 taxa (80 Gastropoda and 15 Bivalvia). Six of the reported taxa are considered dubious
records (5 Gastropoda, 1 Bivalvia). The stratigraphic sequence of Praia Formosa is composed of two main units, about 2-4 meters above present-day sea level. In the lower unit, Patella ulyssiponensis dominates the
fossil assemblage of the basal calcareous conglomerate while Myoforceps arustatus (Dillwyn, 1817) dominates the assemblage associated to a calcareous algae mat. Above a non-depositional hiatus surface, a sandy beach deposit mainly composes the upper unit. Its fossil assemblages are dominated by large amounts of Eruilin castanea (Montagu, 1803) and, in a less extent, Lucinella diwricntn (Linnaeus, 1758) and Ensis minor (Chenu, 1843). The stratigraphic sequence of Lagoinhas, located 7.4 m above present-day sea level, is also composed of two units. A basal conglomerate is fossilized by or passes laterally to a
calcareous algae mat, dominated by Myoforceps aristatus and with abundant Calliostoma pecimens. As at Prainha, these lower units are covered by a highly fossiliferous sandy bach deposit, though thinner, in which Ervlie castanea is the dominant species. Some species with Caribbean or West African affinities, the "Strombus bubonius accompanying
fauna" (Garcia-Talavera, 1990), were found in the lower layers. The upper layer
malacofauna is mainly related to the Mediterranean faunas, similarly to what happens nowadays (Ávila, 2000).
