The ostracods of the Plio-Pleistocene Monte S. Nicola section (Gela, Sicily): an attempted palaeoecological interpretayion

The ostracod assemblages of the Plio-Pleistocene section of Monte S. Nicola (Gela, Sicily) are studied quantitatively. The fluctuations in both the diversity and number of specimens are correlated with a climatic fluctuations as identified by Channell et al. (1992) using planktonic foraminifers. The common occurrence of Agrenocythere pliocenica up to the second half of MPl5 and its spasmodic and rare occurrence at the base of MPl6, demonstrate the gradual disappearance of the psychrosphere in the area and the beginning of the thermospheric environment. In our opinion, the evident species tunover in the same interval supports the hypothesis of a change in Mediterranean circulation from estuarine to antiestuarine