Late Messinian lago-mare ostracod palaeoecology: A correspondence analysis approach

Abstract

In this paper two different Italian late Messinian lago-mare ostracod assemblages, dominated mainly by extinct Paratethyan species, have been analysed by means of Detrended Correspondence Analysis (DCA). The obtained plots have been compared and, with the help of the limited autoecological data on similar living species and geochemical data on the sediments in which they were included, the autoecology and synecology of the lago-mare assemblages have been inferred. In particular, it seems reasonable to suppose that: 1) assemblages made only by pointed candonids are typical of rather deep (possibly less than one hundred meters of depth) and freshwater/oligohaline environments; 2) assemblages mainly composed of Leptocytheridae point to shallow (probably few tens of meters of depth) and mesohaline waters; 3) diversified and even assemblages made both by pointed candonids and Leptocytheridae are common in rather deep (less than one hundred meters of depth) but oligo/low mesohaline environments; 4) Caspiocypris seems rather tolerant of brackish salinities, but prefers shallow environments; 5) Tyrrhenocythere could be an indicator of shallow and fresh/oligohaline waters. 6) Cyprideis is an indicator of shallow waters but can withstand a very wide salinity range.