*4.3. Pteropod Distribution Pattern*

All samples examined for foraminifera include significant amounts of aragonitic pteropods indicating excellent preservation (without any signals of dissolution) along with the strong carbonate preservation potential of the eastern Mediterranean basin [72,93]. A total of 12 species of Euthecosomata (*Heliconoides inflatus*, *Limacina trochiformis*, *Limacina bulimoides*, *Limacina retroversa*, *Creseis acicula*, *Creseis* sp., *Boasia chierchiae*, *Hyalocyclis striata*, *Styliola subula*, *Clio pyramidata* s.l., *Diacria trispinosa*, *Cavolinia* spp.) were identified. Adult specimens, when present, were fragmented (*Cavolinia* spp., *C. pyramidata*). The protoconchs (*Clio, Diacria* and *Cavolina*) made the identification of certain species and genera possible, as they were the only residue left. The down-core variation of their abundance is presented in Figure 4.

Within the basal part of the core sequence, the fauna is composed almost exclusively of the pteropod *L. retroversa*. An additional component is the species *C. pyramidata*, but with very low percentages (<3.5%). Between 153 cm to 127 cm the pteropodal fauna becomes more diverse with the species *H. inflatus*, *D. trispinosa*, *C. acicula*, and *B. chierchiae* appearing in the fauna. The relative abundance of *C. pyramidata* gradually increases (up to 45%), in contrast to the decline of *L. retroversa* (drops to ~40%). The latter disappears completely from the fauna at 105 cm. Between 109 cm and 85 cm the pteropod fauna consists mainly of *H. inflatus*, *C. acicula*, *C. pyramidata*, and *D. trispinosa*, with *L. bullimoides* appearing for the first time at 109 cm. The species *C. pyramidata* and *D. trispinosa* are exponentially decreasing untill, and including, the top of the core sample. In the last 85 cm of the core, *Cavolinia* spp. appears in the fauna, reaching its maximum abundance (58%) at 41.25 cm and 85.5 cm, with the species *H. inflatus* and *B. chierchiae* (15–58% and 3–40% respectively) as additional components. At 65.5 cm, *L. trochiformis* presents a short occurrence and between 65 cm and 60 cm *Creseis* sp. presents its maximum relative abundance (36%). Towards the top of the *core L. trochiformis* and *S. subula* present their highest percentages (~6% and 15% respectively).

**Figure 4.** Frequency curves of the most indicative pteropods in core KIM-2A. Gray bands represent the sapropel S1 sublayers. X axes scales are of 100% and 16% corresponding to the high and low frequency abundances respectively.
