Observaciones sobre algunos criterios tafonómicos usados en la interpretación de asociaciones malacológicas fósiles.

Abstract

In the present paper a revision of some taphonomic criteria commonly used in the interpretation of fossil mollusca assemblages is realized . The field work on living and death assemblages of mollusca in a shallow muddy bottom has been carried out in the coast near Denia (Alicante, Spain). Although the supposed lineal relation between specific abundance and probability of autochthony could explain the structure of part of the considered assemblages, in other a clear disagreement due to a massive incursion of youth elements in observed . By other hand, the possibility of horizontal transport not detectable by these means (anonymous alochtonic fluxes) imposes another limitation to the pretended regularity, With regard to the mechanical breakdown and bioerosion of the shells phenomena, some generally admited biostratinomic criteria are confirmed: although both processes begin when the animal is still alive, they become more important after death, in the exposure phase before burial. The pretended relationship between probability of autochthony and state of preservation hasn't been possible to accept in the death assemblages.