Taxonomy and sexual dimorphism of a new species of Loxoconcha (Podocopida: Ostracoda) from the Pleistocene of the Japan Sea

A new ostracod, Loxoconcha kamiyai sp. nov. in the Family Loxoconchidae, is described from the Pleistocene Omma Formation of Japan. Its geological and geographical distributions suggest that this species was once endemic to the Japan Sea, where it would have evolved until the Pliocene. Since the early Pleistocene, this species would have become extinct within this marginal sea during glacial maxima, probably due to its narrower salinity tolerances and geographical distributions than those of extant species inhabiting the euryhaline environments in other seas. The distributional patterns of pore systems in this species strongly suggest its closest phylogenetic affinities to a living species, Loxocorniculum mutsuense . These two species show a unique adult sexual dimorphism in the anterior element of the hingement. Taking the female hingement morphology as a standard, the male hingement can be explained in terms of heterochrony, i.e. paedomorphosis. Sexual hingement dimorphism with paedomorphosis occurs in only one phylogenetic group of the genus Loxoconcha , which is distinguished by the ontogenetic distributional patterns of pore systems. This morphology may represent relict primitive characters of ancient ostracods and could be an important character for evaluating the history of sexual dimorphism in ostracods since the Palaeozoic.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 153 , 239–251.     

A new early Frasnian (Late Devonian) foraminifer from eastern Taurides (Turkey): Evolutionary and paleobiogeographic implications

A complete Devonian sequence is well exposed in the eastern Taurides, forming more than 1000 m-thick succession of carbonate and siliciclastic sediments. The carbonate succession, stratigraphically ranging from Middle Devonian to early Late Devonian and mostly comprising limestones, dolomitic limestones and reefal limestones, contains abundant and diverse assemblages of foraminifers, corals, stromatoporoids, calcareous algae, bivalves, brachiopods, ostracods, and conodonts. The limestone samples collected from a more closely sampled stratigraphic section have been investigated for their foraminiferal content. The micropalaeontological analyses carried out on these samples have revealed the presence of an early Frasnian foraminiferal assemblage including predominantly unilocular parathuramminid species and multilocular forms of the genera Nanicella, Paratikhinella and Semitextularia? and further indicated the presence of a new genus and a new species Halevikia deveciae n. gen. n. sp. which appears as an important phylogenetic and stratigraphic transitional taxon between the families Baituganellidae n. fam. and Tournayellinidae, the phylogenetic potentiality of which during the Late Devonian is currently probably underestimated.     

A late-surviving Triassic protomonaxonid sponge from the Paris Biota (Bear Lake County,Idaho, USA)

Protomonaxonid sponges are a major group of Cambrian and Ordovician fossils in exceptionally preserved (especially Burgess Shale-type) faunas, but are rare thereafter. Rare examples of apparent surviving lineages are known from the late Palaeozoic and Mesozoic, but by this time more derived groups of sponges have generally displaced them in at least shallow-water (shelf depth) ecosystems. The early Spathian (Early Triassic) Paris Biota includes abundant material of a new leptomitid protomonaxonid, Pseudoleptomitus advenus Botting nov. gen., nov. sp., distinguished by having an unbundled longitudinal skeleton and very weak transverse component. This is the first post-Ordovician leptomitid known, and indicates long-term survival of the group in unknown environments. Its occurrence near storm wave base is similar to the preferred environment of earlier examples of the family, suggesting either ecological rarity or taphonomic reasons for their ∼200-million-year absence from later Palaeozoic rocks.     

The Devonian nekton revolution

Klug, C., Kröger, B., Kiessling, W., Mullins, G.L., Servais, T., Frýda, J., Korn, D. & Turner, S. 2009: The Devonian nekton revolution. Lethaia, 10.1111/j.1502‐3931.2009.00206.x Traditional analyses of Early Phanerozoic marine diversity at the genus level show an explosive radiation of marine life until the Late Ordovician, followed by a phase of erratic decline continuing until the end of the Palaeozoic, whereas a more recent analysis extends the duration of this early radiation into the Devonian. This catch‐all approach hides an evolutionary and ecological key event long after the Ordovician radiation: the rapid occupation of the free water column by animals during the Devonian. Here, we explore the timing of the occupation of the water column in the Palaeozoic and test the hypothesis that ecological escalation led to fundamental evolutionary changes in the mid‐Palaeozoic marine water column. According to our analyses, demersal and nektonic modes of life were probably initially driven by competition in the diversity‐saturated benthic habitats together with the availability of abundant planktonic food. Escalatory feedback then promoted the rapid rise of nekton in the Devonian as suggested by the sequence and tempo of water‐column occupation. □Devonian, diversity, ecology, food webs, nekton, plankton, radiation.     

First decapod crustaceans in a Late Devonian continental ecosystem

The origin and early diversification of decapod crustaceans and their expansion from marine to continental environments are key events in arthropod evolution. Rare fossil decapods are known from the Palaeozoic, and the earliest eumalacostracans with undoubted decapod affinities are the Late Devonian Palaeopalaemon and Aciculopoda, found in offshore marine deposits. Here, we describe a new species of the shrimp Tealliocaris found in floodplain and temporary pond deposits from the Famennian (Late Devonian) of Belgium, together with a rare Palaeozoic assemblage of other crustaceans (conchostracans, notostracans and anostracans) and chelicerates (eurypterids). Tealliocaris walloniensis sp. nov. documents the earliest occurrence of continental decapod crustaceans and indicates that decapods have been part of continental ecosystems at least since the Late Devonian.     

A new well-preserved ostracod fauna from the middle Burdigalian (lower Miocene) of the North Alpine Foreland Basin

The marine middle Burdigalian sediments of the North Alpine Foreland Basin (NAFB) or Molasse Basin are well known for abundant occurrences of benthic foraminifers and ostracods. However, taxonomic studies of ostracod assemblages are comparatively rare and, given its abundance, the group remains heavily understudied. Here we report a new, rich and well-preserved ostracod fauna from the middle Burdigalian Neuhofen Formation at Mitterdorf, in the northeastern part of the NAFB. The material comprises a total of 3029 ostracod specimens. We identified 44 species; all species are described and, with one exception, illustrated. Our material reveals the presence of 17 ostracod species that were previously unknown from the middle Burdigalian in the NAFB, i.e., Cytherella aff. vulgatella, Cytherella aff. méhesi, Bairdoppilata aff. subdeltoidea, Paranesidea? sp., Paracypris aff. aerodynamica, Parakrithe dactylomorpha, Pseudopsammocythere sp., Callistocythere daedalea, Costa aff. reticulata, Ruggieria aff. longecarenata, Heliocythere aff. vejhonensis, Heliocythere sp., Loxocorniculum hastatum, Neocytherideis cypria, Cytheretta cf. tenuipunctata dentata, Cytheropteron cf. ruggierii, and Semicytherura resecta. The palaeobiogeography of the ostracods indicates a relatively open marine Burdigalian connection between the NAFB and the Mediterranean Sea, in agreement with previous work. Our data also suggest that a significant degree of endemism existed in the middle Burdigalian sea of the NAFB, of which previous studies yielded only sparse signs. Moreover, our results indicate that some ostracod species survived the late Burdigalian sea retreat from the NAFB by dispersing eastward into the adjacent regions (Vienna Basin, Carpathian Foredeep), where marine conditions still prevailed. A compilation of all known middle Burdigalian ostracod faunas from the NAFB documents a high species diversity, with over 120 species. Their spatial distribution, with many species being restricted to a single site, suggests heterogenous microhabitats, possibly influenced by small-scale differences in water depth, nutrient availability and oxygenation.     

Sphenophyllum Brongniart (Sphenopsida) from the Upper Devonian of South China

Sphenophyllum Brongniart constitutes a common and important element in the Carboniferous and Permian floras around the world, but its records in the Devonian Period are limited and remain to be investigated with respect to their morphology, anatomy, and distribution. Diversity of Sphenophyllum during Late Devonian in South China was significant with the presence of the well-known species including S. lungtanense Gothan and Sze, S. pseudotenerrimum Sze, and S. changxingense Huang et al. In this article, we describe a new species of the genus, S. fanwanense n. sp., from the Fanwan section of Changxing County, Zhejiang Province, characterized by having at least two orders of axes, with six spoon-shaped leaves attached at the node. A comprehensive review of previous records of Sphenophyllum from the Upper Devonian of South China shows that at least four species (S. fanwanense, S. lungtanense, S. pseudotenerrimum and S. changxingense), each with distinct leaf morphology, occur in South China in the Late Devonian, mostly from the Wutong Formation (Famennian). Given the lack of concrete evidence for anisophylly or heterophylly among the Devonian Sphenophyllum species (and more broadly, the Devonian sphenopsids), we suggest that the development of these features later in the Carboniferous and Permian periods was likely related to an increase in complexity of forest communities through time.     

Wetland megabias: ecological and ecophysiological filtering dominates the fossil record of hot spring floras

Siliceous hot spring deposits form at Earth's surface above terrestrial hydrothermal systems, which create low‐sulphidation epithermal mineral deposits deeper in the crust. Eruption of hot spring waters and precipitation of opal‐A create sinter apron complexes and areas of geothermally influenced wetland. These provide habitat for higher plants that may be preserved in situ, by encrustation of their surfaces and permineralization of tissues, creating T⁰ plant assemblages. In this study, we review the fossil record of hot spring floras from subfossil examples forming in active hot spring areas, via fossil examples from the Cenozoic, Mesozoic and Palaeozoic to the oldest known hot spring flora, the Lower Devonian Rhynie chert. We demonstrate that the well‐known megabias towards wetland plant preservation extends to hot spring floras. We highlight that the record of hot spring floras is dominated by plants preserved in situ by permineralization on geothermally influenced wetlands. Angiosperms (members of the Cyperaceae and Restionaceae) dominate Cenozoic floras. Equisetum and gleicheniaceous ferns colonized Mesozoic (Jurassic) geothermal wetlands and sphenophytes and herbaceous lycophytes late Palaeozoic examples. Evidence of the partitioning of wetland hydrophytic and dryland mesophytic communities, a feature of active geothermal areas, is provided by well‐preserved and well‐exposed fossil sinter apron complexes, which record flooding of dryland environments by thermal waters and decline of local forest ecosystems. Such observations from the fossil record back‐up hypotheses based on active hot springs and vegetation that suggest removal of taphonomic filtering in hot spring environments is accompanied by an increase in ecological and ecophysiological filtering. To this end we also demonstrate that in the hot spring environment, the wetland bias extends beyond broad ecology. We show that ecosystems preserved from the Cenozoic to the Mesozoic provide clear evidence that the dominant plants preserved in situ by hot spring activity are also halophytic, tolerant of high pH and high concentrations of heavy metals. By extension, we hypothesize that this is also the case in Palaeozoic hot spring settings and extended to the early land plant flora of the Rhynie chert.     

Heterochrony of the ostracod hingement and its significance for taxonomy

The hingement of cytheracean ostracods is a very significant character for taxonomy. In some taxa, adult hinge characters develop abruptly at the last moult, whilst in others no significant change of hingement is observed throughout ontogeny. These two types of hinge development are regarded to as 'leap type' and 'gradual type', respectively. In the five major cytheracean families examined, heterochronic relationships were detected in 11 pairs, i.e. in each family, the adult hinge character of the gradual-type taxon corresponds to the A-1 hingement of the leap-type taxon. Furthermore, these 11 heterochronic pairs can be classified into two categories. The first are 'complete pairs', in which the adult hinge character of gradual-type taxa can be almost completely identified in the A-1 of the counterpart leap-type taxa. The second group are 'incomplete pairs', in which the relationship is not so complete. Palaeontological evidence indicates that in most cases the heterochronic evolution is characterized by paedomorphosis, because the leap type always has the older fossil record than the gradual type in each pair. Most of the gradual-type species of complete pairs originated in the Miocene, while all the gradual-type species of incomplete pairs appeared in and after the Pleistocene. Heterochronic changes must occur universally in the cytheracean ostracods, but the degree of completeness of the heterochronic pair seems to be related to the age of speciation.     

The beetle-like Palaeozoic and Mesozoic roachoids of the so-called “umenocoleoid” lineage (Dictyoptera: Ponopterixidae fam. nov.)

The position of Palaeozoic and Mesozoic roachoids and their relationships to crown-group Dictyoptera is an unresolved problem of insect systematics since Hennig's time. This contribution presents new data based on the wing venation of the Early Cretaceous group Cratovitismioidea (so-called “Umenocoleoidea”) supplemented with the discovery of the first Late Palaeozoic representative. As Umenocoleus, type genus of the Umenocoleidae, is considered as a Coleopterida, the roachoids currently included in the Umenocoleidae are transferred to the new family Ponopterixidae, in the new superfamily Cratovitismioidea. Permoponopterix lodevensis, a new ponopterixid genus and species, is described as the oldest representative of this superfamily, from the Middle Permian of the South of France. A new species Ponopterix burkhardi is described from the Lower Cretaceous of Crato Formation in Brazil. Convergent adaptations of tegmina in Coleopterida, Protelytroptera and Cratovitismioidea are discussed.     

New data on the Devonian and Carboniferous Graptolithina (Dendroidea) from Belgium with notes on possible occurrences of Rhabdopleuridae in the Belgian Carboniferous

An old find of a graptolite from the Eifelian Jemelle Formation, combined with the recent discovery of an exceptionally well-preserved specimen from the Upper Frasnian (Matagne Formation), allow documentation of the geologically oldest and youngest dendroid fossils from the Devonian of Belgium. Both are ascribed to the long-ranging genus Callograptus (Acanthograptidae). These records enlarge the sparse knowledge of graptolite diversity and occurrences along the southern margin of Laurussia during the mid-Paleozoic. In Belgium, Devonian dendroids are exclusively known from the Dinant Synclinorium. The Devonian dendroid faunas previously reported from the Eifelian, Givetian and Frasnian of the Ardenne–Rhenish massifs (Belgium and Germany) are of low diversity (one to five species per locality). The specimens, generally inedaquatelly preserved, were ascribed to the genera Callograptus, Dictyonema, Palaeodictyota?, and Ruedemannograptus? In these massifs, Carboniferous dendroids are only known from the Viséan (Moliniacian) Denée Konservat-Lagerstätte. Other but undocumented reports of dendroids (and rhabdopleurids) are from the historical type area of the Tournaisian Stage (Tournai area, Brabant Parautochthon). Rhabdopleuridae from the Viséan–Serpukhovian of the Campine Basin (Turnhout borehole) remain incompletely known in the absence of the previously described material.     

New species of the genus Adelophthalmus (Eurypterida, Chelicerata) found in the Middle Devonian of Khakassia

Two new eurypterid species, Adelophthalmus kamyshtensis sp. nov. and Adelophthalmus dubius sp. nov., are described from the Middle Devonian of Khakassia. The new species are among the earliest known members of the genus Adelophthalmus and the earliest members of this genus known outside Europe and North America.     

Distribution of Recent ostracod species in the Lake Qinghai area in northwestern China and its ecological significance

In order to interpret the climate-change data using the ecological characteristics of the ostracods from the drill cores in Lake Qinghai, the distribution of Recent ostracods was studied in Lake Qinghai area. A total of 34 species belonging to the Ostracoda class of Crustacea were collected from different bodies of water in the Lake Qinghai area, and the ecological information for Recent ostracod species was studied. Among these 34 species, Cypris pubera, Eucypris dulcifons, Ilyocypris sp. 1, Ilyocypris sp. 2, Fabaeformiscandona caudata, Fabaeformiscandona hyalina, Herpetocypris reptans, Prionocypris gansenensis, Potamocypris villosa, Potamocypris smaragdina, Paralimnocythere compressa and Subulacypris sp. were first reported by us in the Lake Qinghai area. Some of the species identified exhibited cosmopolitan distributions, at least in the Holarctic region, but P. gansenensis and Ilyocypris echinata appeared to be restricted to the cold regions in northwestern China.The ecological significance of the primary ostracod species in the Lake Qinghai area was described according to the observations made during our time in the field and according to data from a number of reports. Our results indicate that the species diversity and abundance of ostracods may be related to water salinity in the Lake Qinghai area. The ecological information for ostracods can be used to distinguish different water environments and types based on the characteristics of one species or of an assemblage of several species.     

Ostracods from the Upper Cretaceous–Paleocene Jiaozhou Formation of Jiaozhou,Shandong, China and their biostratigraphic significance

Late Mesozoic–Cenozoic non-marine deposits are well developed in the Jiaolai Basin, eastern Shandong Province, China, yielding abundant fossils including ostracods. In order to further understand the geological settings of the basin during the Late Cretaceous–Paleogene, three boreholes (JK-1, JZK-01 and JZK-02) were drilled in the city of Jiaozhou. Nine genera and sixteen species (including six indeterminate species) of ostracods are described from the Jiaozhou Formation in the three boreholes, including Cypridea, Mongolocypris, Talicypridea, Candona, Eucypris, Cyprois, Porpocypris, Sinocypris and Timiriasevia. Of these, Porpocypris sphaeroidalis Guan, 1978 is reported from northern China for the first time, indicating that this species has great potential to be an indicator of the K/Pg boundary. Correlation of these species with the known Cretaceous–Paleogene ostracod assemblages suggests that the age of the Jiaozhou Formation could be latest Cretaceous–Paleocene in borehole JK-1, Campanian–Maastrichtian in borehole JZK-01, and Maastrichtian–Danian in borehole JZK-02. The exact position of K/Pg boundary, however, is unavailable for the present in the Jiaozhou Formation from boreholes JK-1 and JZK-01.     

Distribution and taxonomy of shallow marine Ostracods from Northern Socotra Island (Indian Ocean) - Yemen

Forty-seven species belonging to 30 genera of ostracods have been identified from Recent shallow marine sediments collected along the northern coastline of the island of Socotra (Indian Ocean). The systematics and distribution of these ostracods are discussed. Three genera, Loxoconcha, Bosasella, and Xestoleberis are found to have high species diversity. The species Loxoconcha ghardaqensis, Moosella striata are best documented in the Red Sea and Gulf of Aden while Kotoracythere inconspicua and Triebelina sertata were found to be the most widespread species. The fauna shows a close affinity to other ostracod assemblages of the Indo-Pacific region, East African coast and Red Sea.     

Middle Permian Ostracods from Tak Fa Limestone, Phetchabun Province, Central Thailand

This paper presents the first Permian ostracod fauna discovered in Thailand. The ostracods are recovered from the Tak Fa Limestone (Middle Permian) in Phetchabun province, central Thailand. The ostracods belong to eight genera and 15 species. Four species are newly described: Sargentina phetchabunensis nov. sp., Geffenina bungsamphanensis nov. sp., Reviya subsompongensis nov. sp. and Bairdia takfaensis nov. sp. The ostracod assemblages characterize a shallow marine, near shore environment at the time of deposition. Except for one species, which shows palaeobiogeographical links between Central Thailand and South China, all the other species are endemic.     

Peronosporomycetes (Oomycota) from a Middle Permian Permineralised Peat within the Bainmedart Coal Measures,Prince Charles Mountains,Antarctica

The fossil record of Peronosporomycetes (water moulds) is rather sparse, though their distinctive ornamentation means they are probably better reported than some true fungal groups. Here we describe a rare Palaeozoic occurrence of this group from a Guadalupian (Middle Permian) silicified peat deposit in the Bainmedart Coal Measures, Prince Charles Mountains, Antarctica. Specimens are numerous and comprise two morphologically distinct kinds of ornamented oogonia, of which some are attached to hyphae by a septum. Combresomyces caespitosus sp. nov. consists of spherical oogonia bearing densely spaced, long, hollow, slender, conical papillae with multiple sharply pointed, strongly divergent, apical branches that commonly form a pseudoreticulate pattern under optical microscopy. The oogonia are attached to a parental hypha by a short truncated stalk with a single septum. Combresomyces rarus sp. nov. consists of spherical oogonia bearing widely spaced, hollow, broad, conical papillae that terminate in a single bifurcation producing a pair of acutely divergent sharply pointed branches. The oogonium bears a short truncate extension where it attaches to the parental hypha. We propose that similarities in oogonium shape, size, spine morphology and hyphal attachment between the Permian forms from the Prince Charles Mountains and other reported Peronosporomycetes from Devonian to Triassic strata at widely separated localities elsewhere in the world delimit an extinct but once cosmopolitan Palaeozoic to early Mesozoic branch of the peronosporomycete clade. We name this order Combresomycetales and note that it played an important role in late Palaeozoic and early Mesozoic peatland ecosystems worldwide.     

Nouveaux brachiopodes Chonetacea du Dévonien de la Cordillère cantabrique (Nord-Ouest d e l'Espagne)

The study of Chonetacean Brachiopods from Cantabrian Mountains allows to recognize several new taxa restricted to this area. A new genus and seven species of which six are new, are described in this paper; their vertical distribution is from Gedinnian to Upper Givetian: Chonetes bediae n. sp., Chonetes? kerforneiRenaud, 1942, Plebejochonetes coliensis n. sp., Plebejochonetes moniellensis n. sp., Luanquella cantabriensis n. g., n. sp., Plicanoplia sotoi n. sp. et Longispina truyolsi. n. sp. The species kerfornei, from the Middle Devonian of Armorican Massif is cited here for the first time from Spain.