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The Mersin Mélange, located in southern Turkey north-west of the city of Mersin, includes blocks and tectonic slices of different origins. The Kilek section in the Mersin Mélange was sampled for a thorough examination of its lithology, biostratigraphy and fossil content. Two samples from the cherty limestone layers within the Huglu Tuffites at the top of the section yielded a rich silicified ostracod fauna of late Early Carnian (based on a two-fold Carnian subdivision) or middle Middle Carnian age (based on a three-fold Carnian subdivision), deposited in an open marine environment, in the outer platform-upper slope zone. We report 121 ostracod species belonging to 53 genera. Two new genera are described: Edithobairdia Forel gen. nov. and Gencella Forel gen. nov., as well as 16 new species: Acanthoscapha mersinella Forel sp. nov., Bairdia hugluensis Forel sp. nov., Acratia kollmanni Forel sp. nov., Citrella? carniana Forel sp. nov., Cytheropteron? schornikovi Forel sp. nov., Eucytherura lacerata Forel sp. nov., Gencella taurensis Forel sp. nov., Kerocythere dorsidenticulata Forel sp. nov., Kerocythere tricostata Forel sp. nov., Monoceratina praevulsaformis Forel sp. nov., Patellacythere tourkosella Forel sp. nov., Polycope kilekensis Forel sp. nov., Ptychobairdia praekristanae Forel sp. nov., Simeonella daginikella Forel sp. nov., Spinomicrocheilinella reliquiaella Forel sp. nov. and Triassocythere tavuscayiriensis Forel sp. nov. The diagnosis of Acratia goemoeryi Kozur is emended. The Kilek fauna retains primitive characteristics illustrated by the first known occurrence of Palaeocopida and Rectonariidae (typical Palaeozoic forms) in the Late Triassic, associated with typical Triassic-modern elements such as thick-shelled and ornamented Bairdiidae and diverse Cytheroidea known from the Middle and Late Triassic worldwide. The unique composition of Palaeozoic and Mesozoic taxa from the Kilek section illustrates unexpected long-term survival in a deep-sea refuge zone following the end-Permian extinction, and the diachronous character of the ostracod recovery in different environments. http://zoobank.org/urn:lsid:zoobank.org.pub:662C3D5C-2B86-4D7B-BDB5-8F8B6A1AD1E7 [ABSTRACT FROM AUTHOR]

The early history of crustaceans is obscured by strong biases in fossil preservation, but a previously overlooked taphonomic mode yields important complementary insights. Here we describe diverse crustacean appendages of Middle and Late Cambrian age from shallow-marine mudstones of the Deadwood Formation in western Canada. The fossils occur as flattened and fragmentary carbonaceous cuticles but provide a suite of phylogenetic and ecological data by virtue of their detailed preservation. In addition to an unprecedented range of complex, largely articulated filtering limbs, we identify at least four distinct types of mandible. Together, these fossils provide the earliest evidence for crown-group branchiopods and total-group copepods and ostracods, extending the respective ranges of these clades back from the Devonian, Pennsylvanian, and Ordovician. Detailed similarities with living forms demonstrate the early origins and subsequent conservation of various complex food-handling adaptations, including a directional mandibular asymmetry that has persisted through half a billion years of evolution. At the same time, the Deadwood fossils indicate profound secular changes in crustacean ecology in terms of body size and environmental distribution. The earliest radiation of crustaceans is largely cryptic in the fossil record, but "small carbonaceous fossils" reveal organisms of surprisingly modern aspect operating in an unfamiliar biosphere. [ABSTRACT FROM AUTHOR]

This study focuses on the sedimentary records of climatic changes in the Küçükçekmece Lagoon over the last 1300 a. The main objective of the study is to investigate the envirenmental conditions in Istanbul during the Little Ice Age (LIA, 600-100 a BP) and Medieval Warm Period (MWP, 1000-600 a BP), which occurred in Europe during the last millenia. The Küçükçekmece Lagoon is situated on the northern shoreline of the Sea of Marmara, west of İstanbul. It has a surface area of 15 km², maximum depth of 20 m and water volume of 145×106m³. The lagoon is connected to Sea of Marmara via a 2 km long natural narrow channel. The main freshwater input is mainly from small sterams and groundwater springs (Altun el al., 2009). The Little Ice Age was a period of mountain glacier expansion during 16th-mid 19th century period during which European climate was strongly impacted (Bradley and Jones, 1993; Jones et al., 1998; Mann et al., 1998, 1999; Mann, 2002). This period begins with a trend towards enhanced glacial conditions in Europe following the warm conditions of the so-called MWP. The LIA terminated with a dramatic retreat of the Alpine glaciers during the 20th century. During this period the temperature was 0.5-0.7°C lower than 1950's avarage. The previous Holocene climate studies in Turkey are rare and mostly confined to the Black Sea and Central Anatolia regions (e.g., Jones et al. 2006; Fleitmann et al, 2009; Kuzucuoğlu et al, 2011). In view of the variability of the present-day climate of Turkey mainly because of its geographic location and topography, and scarcity of data in NW Turkey, the recovery of late Holocene climate records from Küçükçekmece Lagoon (İstanbul) is very important. For this prupose we collected one short interface core (0.6 m) and one 4.5 m long piston core from the Küçükçekmece lagoon. The cores were analyzed for physical properties (magnetic susceptibilty: MS, gamma density, and resistivity) at 5 mm resolution using Multi Sensor Core Logger (MSCL), and multi-elemental analyis at 0.2 mm resolution using XRF (X-Ray Fluoresance) core scanner. The cores were then sampled at 50 mm intervals for total inorganic carbon (TIC), total organic carbon (TOC), and micropaleontological (ostracoda and benthic foraminifera) analysis. The micropaleontological analysis was made in the sand size fraction under binocular microscope. The ostracoda and benthic foraminifera individuals are identified. Suitable species of ostracoda (Loxoconcha sp.) and benthic foraminifera (Ammonia sp.) were picked and analyzed for the stable oxygen and carbon isotope analysis. Four samples were dated using AMS 14C analysis. The ages were calibrated to calendar year by CALIB 6.0 software using INTCAL 9.0 and MARINE 9.0 options. The short and long cores were correlated using the MS profiles and a continuous composite section was constituted. The lithology of the composite core section in general consists of homogenous olive green mud that rarely includes layers of plant remains and laminated intervals. The benthic foraminifera and ostracoda distribution suggests that the lagoon has been brackish over the last 1300 a. The age model was obtained from the calibrated AMS C-14 datings of two total bulk organic carbon and two plant remain layers. The multiproxy data were used to analyze the evaporation/precipitation changes in sediment cores. Increasing MS (SI), Ti (cps) values and decreasing of δ18O-δ13C (% VPDB), Ca/Ti, Sr/Ca ratio and TOC (%wt) values were interpreted to show wet conditions. We also modified the Leng and Marshall's (2004) δ18O-δ13C model for the Küçükçekmece Lagoon. The multi-proxy physical properties, geochemical and stable O- and C-isotope data in Küçükçekmece Lagoon show that wet conditions prevailed during ca 220-70 a BP, 1300-750 a BP and dry conditions during ca 70- 0 a BP, 750-220 a BP. The late (250-100 a BP) and early episodes (600- 250 a BP) of the Little Ice Age period was wet and and dry, respectively. During the the Medieval Warm Period (1000-600 a BP) wet conditions occurred in the region. The climate records also show that decadal-scale wet periods occurred during 340-270 a BP and 680-610 a BP, and dry periods during ca 1050 - 1000 a BP, 1130-1080 a BP and 1260-1210 a BP. Climatic records of Küçükçekmece Lagoon shows similarity with European records in Little Ice Age and Medieval Warm Period. [ABSTRACT FROM AUTHOR]

The carapaces of some ostracode taxa bear reticulate skeletal ridges that outline underlying epidermal cells. This anatomy allows one to identify homologous cells across individuals, to infer the modal sequence of cell divisions that occurs over ontogeny, and to identify individuals with variant cell patterns (e.g., additional or missing cell divisions), even in fossils. Here we explore the variational properties and evolutionary history of this developmental system in the deep-sea ostracode genus Poseidonamicus. Using a sample of over 2000 specimens to capture variation in cell division sequence, we show that phenotypic variation in this system is highly structured: some variants, regions of the carapace, and lineages are much more variable than others. Much of the differences in variation among cells can be attributed to the molt stage in which cells take their final form-cell divisions occurring later in ontogeny are more variable than those earlier. Despite ample variation, only two evolutionary changes in the sequence of cell divisions occur over the 40 Myr history of this clade. The evolutionary changes that do occur parallel the two most common intraspecific variants, suggesting that developmental structuring of variation can have long-term evolutionary consequences. Analysis of the most common variant over the last two molt stages suggests that it suffers a fitness disadvantage relative to the modal form. Such normalizing selection may contribute to the evolutionary conservativeness of this developmental system in the Ostracoda. [ABSTRACT FROM AUTHOR]

Ostracod faunas from the Lower to Middle Ordovician rocks of the Argentine Precordillera Basin (Gualcamayo and Las Aguaditas Formations) are studied. A new family, Garcianidae, is erected. One new genus, Jeanvannieria, and six species are recognized, two of which are new (Jachalipisthia bicornata and Jeanvannieria bulbosa). The diversity and composition of the Precordilleran ostracods is evaluated on the basis of previous taxonomic analysis and the fauna studied here. The diversity is moderate, with a peak of 50 species during the early Caradoc. The composition of the fauna is characterized by the dominance of podocopes with a high percentage of binodicopes and a lack of palaeocopes, which is in agreement with a deep shelf environment. The carbonate slope setting of the Las Aguaditas Formation is the deepest environment yet found with Ordovician ostracods and records a relatively diverse fauna. The presence of Ectoprimitioides suggests biogeographic affinities between the Precordillera and Laurentia. The rest of the fauna contains a high percentage of endemic genera and a mixture of genera with several affinities, Baltic, peri-Gondwanan, and Australian. [ABSTRACT FROM AUTHOR]

New species of ostracods are described from the Tremadoc of the Cordillera Oriental (Argentina). These are among the earliest well-documented records of Ostracoda sensu stricto. The ostracod assemblages are sourced from shallow marine elastics and are dominated by palaeocopes (Eopilla waisfeldae n. sp., Nanopsis coquena n. sp.), and the binodicope Kimsella luciae n. gen. and sp. Eopilla and Kimsella show affinities with species from paleocontinental Gondwana (e.g., Ibero-Armorica, Turkey, Australia, Carnic Alps), but Nanopsis is previously known only from paleocontinental Baltica. This study confirms that two of the major clades of Ordovician ostracods, namely the Binodicopa and the Palaeocopa, were already geographically widespread during the late Tremadoc, suggesting a still earlier origin for these groups, possibly from within the Cambrian to Early Ordovician Bradoriida. Evidence from soft-part anatomy indicates that phosphatocopids, the other group hypothesized to be ancestral ostracods, have apomorphies that preclude them as direct ancestors. The origin of ostracods is more likely to be found within the Bradoriida, a probable polyphyletic group that resembles Early Ordovician ostracods in the external sculpture of their bivalved carapace. Evidence from carapace morphology suggests that the ancestors of true ostracods might lie within the bradoriid groups Beyrichonidae and Hipponicharionidae, a hypothesis that can only truly be tested when more evidence from fossilized soft tissues becomes available. [ABSTRACT FROM AUTHOR]

The ostracode genus Poseidonamicus has been widespread and abundant in deep-sea sediments since the Eocene. Despite its prominent role in a number of evolutionary studies, species identification in this genus is often difficult and phylogenetic relationships among its species are not well understood. Here I present the findings from a comprehensive study of this genus with the purpose of discovering novel phylogenetic characters and clarifying species relationships. I briefly describe the adult carapace and trace sonic of the major morphological changes that occur over the last several instars. I focus particular attention on the arrangement of fossae in the reticulate mesh; these features have been shown in other ostracodes to correspond to underlying epidermal cells. I describe the development of fossae in the region posterior to the adductor muscle scars, and hypothesize a sequence of specific cell divisions to account for the addition of fossae over ontogeny. Phylogenetic characters were derived from many different types of characters, including aspects of carapace shape, the presence and location of pores, characteristics of specific ridges and spines, and the relative position of homologous fossae in the reticulum. A parsimony analysis of 42 characters and 40 operational taxonomic units (36 ingroup and four outgroup) resulted in a Set of optimal trees whose strict consensus is relatively well resolved, well supported, and generally consistent with the order in which taxa appear in the fossil record. The monophyly of Poseidonamicus is supported, as is the monophyly of all deep-sea members of this genus. Within the clade of deep-sea Poseidonamicus, several subgroups are recovered with varying levels of character support. In addition to providing a general framework for understanding morphological evolution in this genus, the results of this phylogenetic analysis have two specific implications for the evolution of sightedness in this genus. First, because Poseidonamicus ocularis is nested deeply within a clade of entirely deep-sea species, its putatively ocular features are probably not related to vision. Second, there has likely been just a single transition from sighted to blind in Poseidonamicus. coincident with its colonization of the deep sea. No support is found for the recent suggestion that sighted shallow-water dwelling Poseidonamicus species may have evolved from blind deep-sea ancestors, although data from additional taxa wilt be necessary to test this hypothesis more fully. [ABSTRACT FROM AUTHOR]

During the earliest Triassic, the neritic environments were completely devastated and the recolonization of biotopes was very slow. Besides some small foraminifera and bivalves, ostracods are among the few neritic organisms that were able to survive and/or to thrive in the inhospitable environments after the disaster events. But the Permian–Triassic boundary marks also a great change in the ostracod assemblages. The Palaeozoic ostracods left room for the “modern” fauna. New data on the Early Triassic neritic fauna in South China (Sichuan and Guangxi Provinces) and bibliographic synthesis on other areas yield a first description of the timing of this turnover. First “typically modern” forms appear already in the Late Permian. The Early Triassic (Griesbachian to Spathian) ostracod faunas display a mixture of Palaeozoic and Mesozoic taxa. Completion of the Palaeozoic–Mesozoic turnover could be located in the Middle Triassic (Anisian). [ABSTRACT FROM AUTHOR]

Ostracods have long been studied by scientists because their fossil remnants provide a valuable tool for the reconstruction of past environmental changes, including climate change and anthropogenic eutrophication. Relatively little is known about the physiology, behaviour and reproductive ecology of recent forms. We argue that filling this gap in knowledge requires stable cultures that can be used in laboratory studies. Here we provide quantitative information on the food preference of the common non-marine ostracod Eucypris virens. Using an experimental device allowing a free choice of eight food items, including both auto- and heterotrophic organisms, observations were carried out on groups of animals from different populations. Our results indicate that E. virens highly prefers spinach and the cyanobacterium Tolypothrix tenuis to other food items. The latter also plays an important role in maintaining the quality of the culture medium and provides a convenient substrate for moulting and egg-laying. As such, we recommend Cyanobacteria like T. tenuis as a food source for long-standing cultures of E. virens, and other non-marine ostracod species. [ABSTRACT FROM AUTHOR]

Abstract: This paper analyzes the lithostratigraphic features and the ostracode associations of the Tortonian deposits located in the western and central sectors of the Guadalquivir basin (S Spain). Eight facies associations are defined (FA-1 to FA-8), being deposited in fluvial to upper bathyal paleoenvironments. The ostracofaune confirms the Tortonian age of these deposits, where three ostracode associations are defined: (a) infralittoral (i.e. Urocythereis favosa, Cytheretta orthezensis, Callistocythere spp.); (b) circalittoral (i.e. Costa batei, Celtia quadridentata, Echinocythereis scabra, Pterygocythereis ceratoptera/jonesii); and (c) outer platform/talus (Henryhowella asperima; Cytherella spp.; Krithe spp.). A comparison with the Tortonian associations of southwestern France and Portugal permits to define a common ostracod zonation for southwestern Europe for this period. [Copyright &y& Elsevier]