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The morphology of fossil remains of Vestalenula (Darwinuloidea, Ostracoda) from Crete (Greece), Serbia and Italy were analysed using morphometric valve variability analysis. Three new species were distinguished and described, Vestalenula angulata n. sp., Vestalenula longissima n. sp. and Vestalenula pliocenica n. sp., and represent the first record of this genus in the Neogene of Italy and Serbia. Vestalenula angulata n. sp. was recorded from the early Messinian of Tuscany, Italy (Baccinello and Velona Basins), Vestalenula longissima n. sp. was collected in the Upper Pliocene (Gelasian) sediment core drilled in the Sabina area (Latium, Italy), and Vestalenula pliocenica n. sp. was collected from the Early Tortonian of Vrysses (Rethymnon Basin, Crete), from the lower Messinian deposits of the Velona Basin (Tuscany, Italy), in the Late Pliocene of the Paludinian Beds (Middle Danube Plain) and Mazgoš deposits (Serbia), and in the Upper Pliocene deposits of the Sabina area (Latium, Italy). Despite the freshwater character of most living species of Vestalenula, the fossil species here analysed were found associated with halotolerant forms, showing they could also withstand oligohaline conditions.

The nine papers collected in this special issue of Micropaleontology are a selection of contributions on presented at the 17th International Symposium on Ostracoda (ISO), which was held in Rome, Italy, on 23rd-26th July 2013, and attended by 141 scientists from 29 countries (see text-figure 1).

Ostracoda are microcrustaceans whose soft parts are enclosed in a bivalve carapace composed of low-Mg calcite. Their small dimensions (0.4 to 2.0 mm on average) and hard parts coupled with a long evolutionary history (from Ordovician to Present) and adaptation to all kinds of aquatic habitat make them a successful taxonomic group for paleontological analyses (Rodriguez-Lazaro and Ruiz-Muñoz, 2012). Ostracoda are mainly benthonic and are very strictly linked to their environment. They are particularly sensitive to salinity, depth, temperature, and bottom substrate, as well as hydrochemistry, nutrient content, and pollution. In addition, their carapace is a source of biogenic carbonate, suitable for geochemical studies (Ito et al., 2003). For all these reasons, Ostracoda represent an excellent proxy for the studies of paleoenvironmental changes during the Phanerozoic (Boomer et al., 2003) aswell as for climate reconstructions during Quaternary as widely demonstrated by the recent volume edited by Horne et al. (2012). The present volume, “Ostracoda as proxies for palaeoenvironmental changes — Selected papers from 17th ISO” assembles selected research on paleoenvironments based on Ostracoda that was presented at the 17th International Symposium on Ostracoda, held in Rome (Italy) from the 22nd to the 26th of July, 2013. Prior to this volume, three special issues of Palaeogeography, Palaeoclimatology, Palaeoecology (Holmes and Horne, 1999; Ikeya et al., 2005; Mischke and Holmes, 2008) have stemmed from the International Symposium on Ostracoda (ISO), one of the largest international micropaleontological conferences with a focus on a single microfossil group. The ISO meetings bring together ostracod researchers from all around the world every 4 years to discuss and exchange classic and novelmethods and applications in the study of Ostracoda in a professional but collegial atmosphere. Presentations at these symposia have often been the prelude to notable and significant publications that have advanced our knowledge on the biology, taxonomy, evolution, and ecology of this group of micro-crustaceans and enhanced their application to the earth sciences. The principle of publishing these works in a special issue of a prestigious international journal such as Palaeogeography, Palaeoclimatology, Palaeoecology is intended to bring the latest developments in ostracod research not just to ostracodologists, but also to the wider earth science scientific community.

The living euryhaline species Cyprideis torosa (Jones) undergoes morphometric variations in size, noding and sieve-pore shape linked to the environmental salinity. In particular it is known that salinity values around 8-9 psu represent the osmoregulation threshold and also the turning point between smaller and greater valve dimensions and prevailingly noded against un-noded valves. The variation of the percentage of round-, elongate- and irregular-shaped sieve-pores on the valves has shown an empiric logarithmic correlation with the water salinity from 0 to 100 psu. Due to this ecologically cued polymorphism, C. torosa represents 28 an invaluable palaeosalinometer for the Quaternary brackish basins. In this paper we attempt to verify whether the ecophenotypical behaviour of the post-evaporitic Messinian species Cyprideis agrigentina Decima was comparable with that of C. torosa. To reach this goal, three morphometric characters have been analysed: 1) size variability; 2) noding and ornamentation; 3) variability of the percentage of the sieve-pore shapes. The palaeoenvironmental interpretation was made using synecological and geochemical approaches [stable isotopes, trace elements, Sr-isotopes and natural radioactivity (NRD)]. For this study, the 250 m-thick Messinian Lago-Mare succession of Eraclea Minoa (Agrigento, Sicily) was chosen for the presence of monotypic assemblages made only by C. agrigentina for around 70 m of thickness. The results of the morphometric analyses showed that: 1) size variations are not related to the salinity changes recognized both from synecological and geochemical analyses; 2) no noded specimens have been recovered along the section; 3) the salinities calculated on the basis of the percentage of the sieve-pore shape are not correlated with the salinities inferred from the synecological and geochemical analyses. Thus in this paper we conclude that C. agrigentina cannot be considered a palaeosalinometer for the Messinian Salinity Crisis. There is a correlation of the 13 C and NRD data with the percentages of sieve-pore shapes, linking them to the oxygen availability at the bottom of the basin.

The 7.5 m long SK13 sediment core, drilled at Lake Shkodra (Albania) bottom depth of 7 m in the central southern part of the lake, was selected for multidisciplinary analysis. Ostracods, Characeae, pollens, and stable isotopes were studied with the aim to reconstruct the past biodiversity and the palaeoenvironmental and palaeoclimatic changes occurred during the Middle-Late Holocene. The chronological framework of SK13 was already known and well constrained through radiometric datings. The sediment core age spans from 4560 cal year BP to present. Thirteen ostracod and five charophyte species were identified. Among them, the ostracods Candona montenigrina and Limnocythere scutariense are endemic of the lake; Candona meridionalis and Paralimnocythere georgevitschi have been collected for the first time in the Lake Shkodra while formerly were considered endemic respectively of Lake Dojran and Lake Prespa; Metacypris cordata, ?Carpathocandona sp., and Cyclocypris sp. were never recorded in the lake and were found only in the lower portion of the sediment core. Among the charopytes, Lychnothamnus barbatus and N. hyalina are recorded for the first time in the lake and occurs with high frequency throughout interval A of core. The faunal composition is quite homogeneous, with the percentages of the different species varying along the sediment core. The main change occurs between 1274 and 1197 cal yr BP, where charophytes disappear abruptly as well as 8 ostracod species out of 13, and the frequency of the remaining 5 species dramatically increases. Moreover at that moment, it occurs also the appearance of a peculiar not-tuberculate morphotypes of Ilyocypris monstrifica. The micropaleontological data suggest a decrease of the lake biodiversity since around 1200 cal years BP linked to the transition between an ancient marshland to a lacustrine environment. This drastic change seems to be independent from any global or local climate changes and could be related to the co-occurrence of two phenomena: 1) the Adriatic sea level rise during the Middle and Late Holocene, that that would have uplifted the base level of the River Bojana causing a decrease of its discharge and, consequently, reducing the drainage of the water from the Shkodra swamp; 2) the periodical change of the River Drin course over the last five centuries, which, when deviated into the Bojana river, blocked the River Bojana outflow.

Ilyocypris Brady & Norman, 1889 is a widespread freshwater ostracod genus including about 30 living and 190 fossil species. The specific identification of the living Ilyocypris relies mainly on the appendages, being an identification exclusively based on valves rather complicated because of the high intraspecific variability of their characters in several species. This study aims to test the taxonomic significance of the carapace characteristics through the examination of specimens unambiguously identified on the basis of their soft part morphology, in order to provide useful taxonomic criteria for the identification of Ilyocypris shells in fossil assemblages. Sixty-five ilyocypridid specimens collected in mainland Italy and surrounding islands were analysed. All specimens were dissected and soft parts checked in light microscopy. The patterns of valve surface ornamentation and of marginal ripplets were examined by electron microscopy. Moreover, the geometric morphometric analysis of the valve outlines was performed. Sixty-two specimens could be easily accommodated in eight Ilyocypris species (I. bradyi, I. decipiens, I. getica, I. gibba, I. hartmanni, I. inermis, I. monstrifica, and I. salebrosa) according to the morphology of their appendages. Three additional specimens, with soft parts typical of Ilyocypris but clearly distinct valve morphology, were left in open nomenclature. Our results show that the outline analysis is often a valid tool to discriminate between different species. Conversely, valve ornamentation displays different degrees of intraspecific variability in some Ilyocypris species. The marginal ripplets are constant within each species, but they do not always mirror the patterns reported by other authors; therefore, we do not consider them as reliable diagnostic character for specific determination. This study confirms that the identification of Ilyocypris species requires accurate description of appendages as well as external and internal carapace characteristics, and stresses the advantage of a combined neontological and paleontological investigation in solving taxonomic problems related to non-marine ostracods.

The aim of this paper is to re-describe LIVENTAL’s (1929) species through the SEM pictures of the specimens included in various historical collections deposited at the Micropaleontological Laboratory of the VNIGRI, St. Petersburg, Russia, since the original Livental’s collection seems to be lost as well as the Azerbaijan collections by Agalarova (AGALAROVA, 1956, 1967; AGALAROVA et al., 1940, 1961). In particular, the revision is based on the VNIGRI collection AZNII27 of L.N. Klein who studied the ostracods of the Azerbaijan area of Babazanan (KLEIN, 1960, the same area studied by LIVENTAL, 1929) and on several other collections from Turkmenistan, the Caucasus and Euxinic/Black Sea? Basin included both in historical collections (Mandelstam, Luebimova, Rozjeva, Stepanaitys) as well as on new findings from the Euxinic Basin. The discussion on each species is accompanied by its synonymy, and an updated geographical and stratigraphical distribution based on the new chronostratigraphical data of KRIJGSMAN et al. (2010) and VAN BAAK et al. (2013). In those few cases where the Livental’s species are still living in the Caspian or Black Sea, the soft parts are described and the ecological parameters given.

During September 2003 several cores were drilled from the Albanian side of Lake Shkodra. Among them, a 7,8 m long composite core (SK13), drilled at a lake bottom depth of 7 m in the central southern part of the lake (42°6’11.65”N, 19°25’18.96”E) has been selected for multidisciplinary analysis. Ostracods, characeae, pollen, CaCO3 content and stable isotopes were studied with the aim to reconstruct the palaeoenvironmental and palaeoclimatic changes occurred during the Late Holocene. The chronological framework of SK13 was established through the recognition of four well-dated tephra layers and four 14C accelerator mass spectrometry measurements; the sedimentation rate has been calculated as spanning between 1.1 and 3.0 mm/yr in the different portions of the composite sediment core (SULPIZIO et al., 2010, VAN WELDEN et al., 2008).

The Legnagnone section (North-eastern Apennines) represents one of the few shallow water records of the onset of the Messinian salinity crisis. Here we present a detailed description of a ~200 kyr time interval encompassing the pre-/syn-evaporitic transition based on a multidisciplinary approach, integrating sedimentological, bio-magnetostratigraphical, palaeontological and stable isotope data. Such a shallow water setting is potentially more sensitive to the palaeoenvironmental change leading to the MSC than the more often studied deeper Mediterranean basin. The aquatic palaeoenvironmental reconstruction proposed here is based on the study of foraminifer, ostracod and mollusc assemblages. It depicts a change from infralittoral (20–50 m) to inner circalittoral environment (60–100 m) that, since 6.12 Ma, was progressively affected by a reduction of oxygen at the sea floor punctuated by short-lived anoxic events. At least three cooling events have been recognized on the basis of relative abundance data in mid to high altitude pollen, which, before 6.03 Ma, are in phase with abundance peaks of Turborotalia spp., a taxon indicating eutrophic and cool surface waters. The absence of stress-tolerant benthic foraminifers during these peaks points to strong ventilation episodes triggered by a generally cooler climate. The proximity of a deltaic system and the consequent riverine input probably caused a salinity decrease of the surface waters, hindering the proliferation of planktonic foraminifers in the water column, which prevalently occur in short influxes and disappear at ca. 6 Ma. Our results suggest that the onset of the crisis occurred during a phase of relative sea level high stand, whereas no evidences of sea level drop can be envisaged. The palaeoclimatic reconstruction based on palynological data indicates the dominance of a “subtropical humid forest” vegetation type, where fresh water swamps are well represented. From 6.03 Ma onward, the transition to the salinity crisis is marked by more pronounced cyclical expansions of the temperate broad-leaved deciduous forest, along with herbaceous taxa. The establishment of the strongly evaporative condition at the crisis onset is not associated with major vegetational changes towards drier conditions, but linked to a sudden increase of δ18O and the disappearance of benthic foraminifers just prior to the deposition of the 1st laminated carbonate, which represents the base of the Primary Lower Gypsum unit.

The relationship between ostracod and macrophyte communities has been seldom studied, especially in urban parks. The main purpose of this research is to explore such a relationship in the area of Rome, and in particular in the Appia Antica Regional Park (Rome, Italy), to provide information about the environmental characteristics influencing both the assemblages and to document for the first time the distribution of freshwater ostracods in an area inside the city of Rome. The survey has considered different water bodies: springs, channels, ditches and a pond. Chemical and physical parameters were measured during the ostracod sampling in 13 sites during the 4 different seasons. The ostracod assemblage includes 11 species whereas the macrophyte community is formed by 17 species. Their link with the measured abiotic parameters has been studied through several statistical analyses: cluster analysis, non-metric multidimensional scaling and canonical correspondence analysis. The results clearly separate the investigated area in one sector where COD and phosphates are the driving factors and another sector where inorganic nitron ions, pH and conductivity are the main influencing factors. To better understand the ostracod-macrophyte interaction, Spearman rank-order correlation analysis was performed, confirming such a link. Although the macrophyte community is clearly affected by human pressure, the relationship with the ostracod assemblages seems well established and identified by exclusive pairs or groups of species. Among them, the Cypria lacustris-Lemna minuta duo is of considerable importance, being L. minuta an exotic species, known as an invasive weed in some areas of Europe and spread in Italy only recently. The fact that the 13 sites were characterized by different public access regulation has been partially mirrored by both ostracod and macrophyte distribution since the majority of the sites characterised by the highest diversity are those with restricted access. In general, notwithstanding the anthropic pressure, the occurrence of different kinds of water bodies has allowed the development of ostracod and macrophyte associations, which are rarely represented in an urban park.

The historical site of the Monte Mario lower Pleistocene succession (Rome, Italy) is an important marker of the Pliocene/Pleistocene boundary. Recently, the Monte Mario site was excavated and restudied. A spectacular angular unconformity characterizes the contact between the Monte Vaticano and the Monte Mario formations, which marks the Pliocene/Pleistocene boundary. Biostratigraphical analyses carried out on ostracod, foraminifer, and calcareous nannofossil assemblages indicate an Early Pliocene age (topmost Zanclean, 3.81–3.70 Ma) for the underlying Monte Vaticano Formation, whereas the Monte Mario Formation has been dated as early Pleistocene (Santernian, 1.66–1.59 Ma). Palaeomagnetic analyses point to C2Ar and C1r2r polarity chrons for the Monte Vaticano and the Monte Mario formations, respectively. The Monte Mario Formation consists of two obliquity-forced depositional sequences (MM1 and MM2) characterized by transgressive systems tracts of littoral marine environments at depths, respectively, of 40–80 m and 15–20 m. The data obtained from foraminifer and ostracod assemblages allow us to reconstruct early Pleistocene relative sea-level changes near Rome. At the Plio/Pleistocene transition, a relative sea-level drop of at least 260 m occurred, as a result of both tectonic uplift of the central Tyrrhenian margin and glacio-eustatic changes linked to early Pleistocene glaciation (Marine Isotope Stage 58).

Dans ce travail, les ostracodes trouv´es dans dix complexes coralliens du Mioc`ene sup´erieur construits par Siderastrea, Tarbellastrea et Porites, localis´es dans la plaine de Messara (zone m´eridionale du bassin de l’Iraklion, Cr`ete centrale) sont ´etudi´es et illustr´es. Cinq diff´erentes associations caract´eristiques des divers environnements marins ont ´et´e reconnues par : (1) association des couches silteuses basales, caract´eris´ee par des esp`eces typiques des eaux marines du domaine infralittoral sup´erieur, parmi lesquelles Cyamocytheridea meniscus, Cyamocytheridea obstipa, Cyamocytheridea dertonensis, Cytheretta semiornata et Nonurocythereis seminulum sont tr`es repr´esent´ees ; (2) association des couches r´ecifales avec Grinioneis haidingeri, Aurila cicatricosa, Cimbaurila diecii, Tenedocythere cruciata, Pokornyella italica et Callistocythere quadrangula dominants qui indiquent un environnement marin infralittoral sup´erieur stable, caract´eris´e par des eaux chaudes et bien oxyg´en´ees ; (3) association des couches silteuses interpos´ees entre les complexes coralliens, parmi lesquelles Neomonoceratina laskarevi, Cytheridea acuminata, Phlyctenophora farkasi, Aurila albicans Callistocythere spp., Xestoleberis communis et X. dispar sont dominants. Ces esp`eces indiquent des eaux peu profondes avec v´eg´etation aquatique ; (4) association des couches silteuses sup´erieures, domin´ee par la pr´esence du genre Xestoleberis, caract´eristique des environnements marins moins profonds et tr`es riches en flore aquatique et (5) association des couches argilosilteuses terminales, domin´ee par Hemicytherura defiorei, Ostracods from ten Late Miocene coral reef complexes built by Siderastrea, Tarbellastrea and Porites, cropping out in the Messara Plain (southern Iraklion basin, central Crete), have been investigated and five assemblages have been recognised, which point to different marine environments: (1) assemblage from the basal sandy silts, dominated by very shallow inner-infralittoral species, such as Cyamocytheridea meniscus, Cyamocytheridea obstipa, Cyamocytheridea dertonensis, Cytheretta semiornata and Nonurocythereis seminulum; (2) assemblage from the coral reef complexes within which Grinioneis haidingeri, Aurila cicatricosa, Cimbaurila diecii, Tenedocythere cruciata, Pokornyella italica and Callistocythere quadrangula are dominant and point to a stable inner-infralittoral environment characterised by warm, quiet and well-oxygenated waters; (3) assemblage from the silts intercalated among the coral reef complexes, mainly characterised by Neomonoceratina laskarevi, Cytheridea acuminata, Phlyctenophora farkasi and Aurila albicans together with Callistocythere spp., Xestoleberis communis and Xestoleberis dispar, which points to a very shallow marine environment rich in aquatic vegetation; (4) assemblage from the upper silts, which records the absolute dominance of Xestoleberis species, reflecting a very shallow and highly-vegetated environment and (5) assemblage from the uppermost silty clays, dominated by Hemicytherura defiorei, Xestoleberis spp. and Palmoconcha dertobrevis, accompanied by Acanthocythereis hystrix, Cytherella scutulum, Bairdoppilata conformis, Semicytherura spp., Krithe sp., Cytheropteron alatum, Bythocypris sp. and Pseudocythere caudata, which suggest deeper marine environments probably located in the outer infralittoral/inner-circalittoral zones. The studied section has been dated by means of calcareous nannoplankton to be not younger than Zone MNN9 (Early Tortonian), which is the biostratigraphical datum recorded in the fine-grained deposits that overlie the coral reef complexes. An age not older than Tortonian can be inferred by the stratigraphical distribution of the recognized ostracods. Thus, the coral reef complexes have been tentatively referred to the Early Tortonian.

In this paper the preliminary results of the analyses on the ostracod assemblages coming from the Middle– Late Pliocene Tiberino Lake (Umbria, central Italy) are discussed. Three sections have been investigated, Cava Toppetti and Fosso Bianco, whose sediments record a deep lacustrine facies, and Dunarobba, which represents the littoral facies of the lake. Cava Toppetti and Fosso Bianco ostracod assemblages are very similar, made exclusively by Candonidae (six genera and eleven species, nine of which are new) and Limnocytherinae (one genus including one new species), while at Dunarobba the assemblages are more diversified, including Candonidae (four genera and five species), Limnocytherinae (one genus including one new species), Ilyocyprididae (one genus and three species), Cytherideinae (one genus and two species) and Cyprididae (two genera and two species, one of which is new). On the whole, the Tiberino Lake ostracod assemblages seems to be characterised by a high degree of endemism, particularly in the deep lacustrine facies (up to 83%) and, among the Candoninae, intralacustrine speciation is recognizable for genera Candona (Neglecandona), Sirmiella and “Caspiocypris”. This latter gives rise to a “species flock”. The characteristics of the collected ostracod fauna, coupled with the long duration of the lacustrine sedimentation (1.8 Ma) concur to suggest that the Middle–Late Pliocene Tiberino Lake was a “palaeo–ancient lake”.

A high-resolution stratigraphic model for the uppermost Messinian deposits of the Mediterranean basin is here proposed. The model provides new constraints for calibrating the time and space distribution of palaeoenvironmental proxies of the final phase of the Messinian salinity crisis (MSC), characterized, after the main phase of massive evaporite precipitation, by the progressive and generalized establishment of brackish to freshwater aquatic environments throughout the Mediterranean basin (‘Lago Mare event’). The corresponding stratigraphic unit, bounded by the intra-Messinian unconformity (MES) at the base (~5.6 Ma) and the M/P boundary at top (5.33 Ma) is split into two sub-units by a minor unconformity marking a sharp facies change. The lower sub-unit (p-ev1) is localized in deepest and/or strongly subsiding basins and is commonly characterized by ‘regressive’ depositional trends. It records the transition from hyper- to hypohaline conditions over a short time span characterized by an acceleration of tectonic processes in many Mediterranean geodynamic contexts. The upper sub-unit (p-ev2) is more basin-wide distributed and records the generalized periodic activation of catastrophic flood-dominated fluvio-deltaic depositional systems, indicating important modifications in the drainage areas and/or in fluvial runoff. In this sub-unit four to five precessional cycles are usually recognized below the Miocene/Pliocene boundary, allowing basin-wide correlations and suggesting to place its basal age at around 5.42 Ma. While p-ev1 records the local and ephemeral development of Lago Mare environments with low-diverse, pioneer taxa, p-ev2 is marked by the diffusion of conspicuous brackish to freshwater fossil assemblages of increasing diversity and complexity upwards. The change is best approximated by the boundary between the two sub-units. No clear evidence of normal marine conditions established before the Zanclean flooding have been recognized. Converging sedimentary evolution and paleontologic record suggest that the last MSC phase was characterized by a dilution of the surface waters of a large, residual Mediterranean water body with strongly reduced ocean connections. These conditions likely resulted from a positive feedback loop between processes (increase of fluvial runoff, generalized subsidence, base-level rise, enlargement of shelf areas) promoting the establishment of progressively larger, more stable intra-basinal connections and water exchanges with the Paratethyan basins, up to the final full reopening of the Atlantic gateways.

Two possible alternative interpretations of the claimed Zanclean age (Popescu et al., 2007) of two historical lithostratigraphic units of the Northern Apennines, usually referred to as Late Messinian in age and recording the so called Lagomare final event of the Messinian salinity crisis (MSC), are here discussed. The wrong age attribution of the Colombacci and ‘‘tetto’’ Fms. is ruled out based on data from the Maccarone and other sections showing that the Colombacci-Argille Azzurre Fm. boundary is basin wide synchronous and coincident with the Miocene-Pliocene boundary as far as it has been formally defined in the Eraclea Minoa GSSP. Alternatively, the opportunity of emending the Zanclean GSSP to a stratigraphically lower horizon recording the first evidence of marine influences in the Mediterranean following the MSC peak, seems not suitable, as (1) the marine signature of uppermost Messinian deposits is weak and still controversial and (2) no significant bio- and magnetostratigraphic events, well chronologically defined and recognizable at a global scale appear to be available to such a purpose.