Paleobiocenosis de Heterostegina en sedimentos de origen litoral de la Fm. Calcarenita de Niebla (Mioceno superior, Cuenca del Guadalquivir, SO España)

Abstract

A taphonomic analysis of some lumaquellic levels of Heterostegina interbedded in the basal sandy unit of the Calcarenita de Niebla Fm. (Huelva, Spain) is presented. However, it is made a revision of the main factors that determine nummulitid distribution in recent marine environment and the interest of their study for the paleobatimetric and trophic conditions inference. The integration of all these data with paleobiologie analysis deduced from fossiliferaI assemblage and with the sedimentological data of these levels, allow us to interprete their lumaquellic origin as true paleobiocoenosis in a transgressive coastal context with deltaic influences. We also discuss some morphofunctional aspects on Heterostegina test, that apparently present some contradictions in relation to the environmental conditions considered