A NEW PLEISTOCENE VALVATA SPECIES FROM LAKE BEY a EHIR AND TWO NEW GYRAULUS SPECIES FROM LAKE E Ð IRDIR ( MOLLUSCA : GASTROPODA : VALVATIDAE , PLANORBIDAE ) IN TURKEY

Recently collected samples from lakes Beyoehir and Eðirdir in Turkey contained one new Pleistocene Valvata which we describe here as †Valvata beysehirensis n. sp. In addition we found two new species of Gyraulus, named G. egirdirensis n. sp. and G. taseviensis n. sp. These species are compared with members of the genera Valvata and Gyraulus known so far from Turkey.


MATERIAL AND METHODS
The snails were collected by hand.The shells were measured under a Zeiss stereomicroscope with a calibrated eyepiece; the photographs were taken with a Leica R8 camera system with a digital adapter.Dating of fossil samples was based on the isotope 14 C analysis with the use of atomic mass spectrometer ( 14 C AMS).
The type material is stored at the Zoological Museum Hamburg (ZMH), Museo Civico di Storia Naturale, Milano, Italy (MSNM), and the collection of ALBERTO GIROD (AGMal).In addition, paratypes have been sent to Prof. Dr. M. ZEKI YILDIRIM (University Burdur, Turkey).

SAMPLING SITES
Lake Beyºehir, 1,123 m a.s.l., 656 km 2 , has a maximum depth of 10 m (IªILDAR 2010).The lake (Fig. 1) occupies the northern basin of the Beyºehir depression, which extends southwards to Lake Suðla.The raised shorelines and Quaternary fossils indicate that during the Pleistocene pluvial periods the levels of the two lakes rose up to that of karstic outflows (EROL 1980).The beach ridges are between 10 and 25 m above the present water level (EROL 1978).
Beyond the existing shore, to the southeast of the lake, widespread outcrops of ancient lacustrine deposits are located, both north of Beyºehir towards Kireli and along the road which runs eastwards along the valley bottom in the direction of Konya, via Üçpinar.The strata from which the samples were obtained are exposed on a hillock to the west of the national road D695, at the latitude of Çiftlikköy, just south of the turning for this village.
The deposit crops out at 1,135 m a.s.l. and is cut by a disused quarry where the visible strata are about 5 metres thick, with alternating layers of carbonates and gyttja.Lake Eðirdir (Fig. 1), 917 m a.s.l. and 482 km 2 , is the fourth largest lake in Turkey after Van Gölü, Tuz Gölü ('Salt Lake') and Beyºehir Gölü.The average water depth is 7-8 m, with the maximum of 15 m.In summer stretches of shore emerge, with notable accumulations of mollusc shells.These are natural thanatocoenoses made evident by the seasonal drop in the water level, formed by wave action that pushes the mollusc shells up the beach, building up the accumulations.They rest on gravelly deposits from which the waves have removed the finer sediments.Samples were collected in the Hoyran lowlands, between the villages of Taºevi and Gençali, from a small lake or pond at the NW.margin of Lake Eðirdir and separated from it by a tree-covered beach ridge.It is fed by abundant spring water which supports plentiful submerged aquatic vegetation.Its water flows into Lake Eðirdir, with which it is occasionally connected only during water level highstands.The difference between high and low water levels can be as high as 5 m (GÜLLE et al. 2008).

RESULTS
The samples collected by A. GIROD in 2000 and 2002 contained one new Pleistocene Valvata species and two new Gyraulus species.Unfortunately we had only empty shells for identification, however, these are characteristic enough to describe the species as new.

Genus Valvata O. F. Müller, 1773
Type species: Valvata cristata O. F. Müller, 1774.†Valvata beysehirensis n. sp.   6) is glossy with 3.5 whorls which are circular, but angled at the top near the suture (Fig. 5, arrow).The surface is finely striated (Fig. 4).The first whorls are flat and only the body whorl is descending.The suture is deep, especially at the body whorl (Fig. 5).The umbilicus is wide and the first whorls are clearly visible (Fig. 6).The shell is 3.0-3.4mm in diameter and 1.4-1.6 mm in height.
Differentiating features: At first glance the shell is similar to that of Valvata cristata but in †V.Remarks: Two samples of valvatid shells from gyttja layers yielded the following 14 C AMS dates: sample Bey 3 -(GrA-53007) 46,000±850-600 years BP d 13 C -7.38‰; sample Bey 5 -(GrA-53009) 44,450±650-550 years BP d 13 C -6.66‰.Since these gyttja layers are overlain by thick carbonate sediments, contamination by young carbon from percolating meteoric water after the retreat of the lake must be taken into account (ROBERTS et al. 1999).The error in age determination could be between 4 and 6 ka.The two dates obtained are quite similar and correspond to the late Middle Pleistocene.The raised beaches of the Beyºehir-Suðla Basin at 1,130 and 1,135 m a.s.l.represent the contact between the Upper and Middle Pleistocene (EROL 1978); the dates from the new samples collected from between 1,130 and 1,133 m thus fit comfortably into this period, notwithstanding the error margin.Remark: Gyraulus species are sinistral, but the underside is the functional upper side of the snail.In the following description we always refer to the functional sides.
Etymology: Named after the lake where the species lives.
Description: The whitish shell is silky with fine growth lines (Fig. 9).The shell consists of 3.5-4 whorls, which are regularly and rapidly increasing with a deep suture on both sides (Figs 9,10).The expanded body whorl is keeled and it is not deflected.The first whorls are immersed on both sides.On the surface of both sides 2-3 spiral ribs are visible .The shell is of medium size, 5.0-5.9mm in diameter and 1.4 mm in height.Differentiating features: The species is characterised by its prominent keel (Fig. 12), and the spiral ribs on the shell, which are not found in any other Gyraulus.
Etymology: Named after the village near which the species was found.
Description: The whitish to light-corneous shell is silky to glossy (Fig. 14), transparent, smooth with fine growth lines.The shell consists of 3.5-4 whorls, which are regularly and rapidly increasing with a deep suture.The first whorls are immersed slightly on the upper side and deep on the underside with a wide umbilicus (Fig. 15).The body whorl is angled and deflected (Fig. 16).The shell is of medium size, 5.0-6.0 mm in diameter and 1.4-1.6 mm in height.
Differentiating features: At first glance the shell looks like that of Gyraulus bekaensis Glöer et Bössneck, 2007, with its type locality far away in Lebanon (GLÖER & BÖSSNECK 2007).However, in the latter species the last whorl is not deflected.The deflected body whorl and the angled shell are reminiscent of Gyraulus piscinarum acutissima Schütt et ªeºen, 1993, described from Lake Gölbaºý (SCHÜTT & ªEªEN 1993), in which the upper side of the shell has a prominent reticulate sculpture, while the shell of G. taseviensis n. sp. is smooth.

DISCUSSION
All the associated species found together with †Valvata beysehirensis n. sp. in the same gyttja layer showed that they occurred contemporarily.Because all the other species still occur in Turkey it is possible that also †Valvata beysehirensis n. sp. may be found alive.
In order to identify the species of Gyraulus collected by A. GIROD, we had to compare them with the members of Gyraulus previously known from Turkey.The differences between the new species described above and the Gyraulus spp.which live in Central Eu-
Figs 7-8.The sampling site at Lake Eðirdir