Succession of late Pleistocene and Holocene ostracode assemblages in a transgressive environment: A study at a coastal locality of the southern Baltic Sea (Germany)

The present study documents the hydrological and coastal evolution of a southern Baltic Sea lagoon by analyzing ostracode associations. Six ostracode zones were distinguished from a 13.5 m long vibro-core in the Pudagla Lowland (NE Germany) using SPLITINF (binary divisive clustering) zonation. Sediments of a Pleistocene freshwater stage are overlain by deposits of a Preboreal brackish water environment, which are not related directly to the development of the Baltic Sea. Different boreal freshwater habitats developed in the study area until marine water protruded the Pudagla site in the course of the Littorina Transgression. A gradual succession in the species assemblage reflects the subsequent transgression. Freshwater species (i.e., Metacypris cordata, Fabaeformiscandona protzi, and Herpetocypris sp.) are substituted in pre-Littorina inland waters (ca. 7.2 14C ka BP) by halotolerant species (i.e., Candona angulata, Sarscypridopsis aculeata, and Plesiocypridopsis newtoni; ca. 6.5 14C ka BP) and finally, the ostracode fauna is dominated by Cyprideis torosa associated with Cytheromorpha fuscata and Loxoconcha elliptica when brackish–marine water conditions are established (ca. 6.4 14C ka BP).