TAFONOMÍA Y SEDIMENTOLOGÍA DE LA PALEOBIOTA ESTUARINA EN LOS CERROS BARBUDAL (COSTA RICA) SEPULTADA POR VULCANISMO NEÓGENO

Abstract

A marine taphocoenosis constituted by brachiopods and mollusks (bivalves and gastropods) wasfound interbedded in a Neogene volcaniclastic sequence (ignimbrites and tuffites from Bagaces Formation). Itis remarkable the finding of the first fossils of inarticulate brachiopods in Central America: Glottidia sp. Theseremains are well preserved because their calcium phosphate skeleton, while those from the mollusks, composedby calcium carbonate, are only preserved as internal casts. The fossils are now located just 10 m a.s.l., in spiteof their age of several million years. This may be due to a complex equilibrium between the region’s subsiden-ce and uplifting history.