Revision of the superfamily Acrotheloidea (Brachiopoda,class Linguliformea,order Lingulida) from the Lower and Middle Cambrian of the Siberian Platform

This paper continues our revision of Yu.L. Pelman’s collection of the superfamily Acrotheloidea (phosphatic brachiopods) and of our own material from the Early–Middle Cambrian of the Siberian Platform. The following representatives of the superfamily Acrotheloidea (order Lingulida, class Linguliformea) are restudied and revised based on new techniques: the genus Botsfordia (family Botsfordiidae Schindewolf, 1955) and the genera Acrothele, Eothele, and Orbithele (family Acrothelidae), which are widespread on the Siberian Platform. Only one out of the three Acrothele species described by Pelman is recognized as a valid species, and one new species of this genus that comprises some part of the brachiopods that Pelman figured and placed in another taxon is described. All these species are described using data on shell microsculpture and microstructure. In addition, the genera Eothele and Orbithele are described for the first time from the Siberian Platform.     

Mesophotic reef fish assemblages of the remote St. Peter and St. Paul’s Archipelago,Mid-Atlantic Ridge,Brazil

Mesophotic reef fish assemblages (30–90 m depth) of the small and remote St. Peter and St. Paul’s Archipelago (SPSPA), Mid-Atlantic Ridge, Brazil, were characterized using remotely operated vehicles. Ordination analyses identified distinct fish assemblages in the upper (30–50 m) and lower (50–90 m) mesophotic zones, the former characterized by high abundances of species that are also abundant at euphotic reefs (Caranx lugubris, Melichthys niger, Stegastes sanctipauli and Chromis multilineata) and the latter dominated by two mesophotic specialists (Prognathodes obliquus and Chromis enchrysura). Planktivores dominated fish assemblages, particularly in the upper mesophotic zone, possibly due to a greater availability of zooplankton coming from the colder Equatorial Undercurrent in mesophotic depths of the SPSPA. Turf algae, fleshy macroalgae and scleractinian corals dominated benthic assemblages between 30 and 40 m depth, while bryozoans, black corals and sponges dominated between 40 and 90 m depth. Canonical correspondence analysis explained 74 % of the relationship between environmental characteristics (depth, benthic cover and complexity) and structure of fish assemblages, with depth as the most important independent variable. Juveniles of Bodianus insularis and adults of P. obliquus and C. enchrysura were clearly associated with branching black corals (Tanacetipathes spp.), suggesting that black corals play key ecological roles in lower mesophotic reefs of the SPSPA. Results from this study add to the global database about mesophotic reef ecosystems (MREs) and provide a baseline for future evaluations of possible anthropogenic and natural disturbances on MREs of the SPSPA.     

Revision of the Early-Middle Cambrian Lingulida (Brachiopoda) from the Siberian Platform

Based on Yu.L. Pelman’s lingulid collection and our own material, the Early-Middle Cambrian genus Eoobolus, which was widespread on the Siberian Platform, is revised. The Siberian members of this genus have previously been assigned to Lingulella. Two out of these six members are recognized as valid species: Eoobolus siniellus (Pelman) and E. variabilis (Pelman). Lingulella acuta Pelman and L. linguata Pelman are considered here to be junior synonyms of E. priscus (Poulsen, 1932). The valid species are redescribed and their stratigraphic and geographic ranges are given. A new species, E. pelmani sp. nov., is described. New data on the Eoobolus microornamentation and shell structure are provided.     

First record of <Emphasis Type="Italic">Pojetaia runnegari</Emphasis> Jell, 1980 and <Emphasis Type="Italic">Fordilla</Emphasis> Barrande, 1881 from the Middle East (Taurus Mountains,Turkey) and critical review of Cambrian bivalves

Cambrian bivalves from the Middle East are reported here for the first time. They come from early “Middle Cambrian” and latest “Early Cambrian” limestones of the lower Çal Tepe Formation at the type locality (near Seydi?ehir, western Taurides). The majority of the new findings consists of Pojetaia runnegari Jell, 1980, but a few specimens of Fordilla sp. represent the first report of this genus from “Middle Cambrian” strata. Based on a compilation of the hitherto reported, but mostly revised Cambrian bivalves, the today widely accepted taxa are discussed. The genera Pojetaia Jell, 1980 and Fordilla Barrande, 1881 are critically evaluated, and three valid species are included in Pojetaia: P. runnegari Jell, 1980, P. sarhroensis Geyer and Streng, 1998, and—with limitations—P. ostseensis Hinz-Schallreuter, 1995. Fordilla also includes three species: F. troyensis Barrande, 1881, F. sibirica Krasilova, 1977, and F. germanica Elicki, 1994. The Cambrian genera Tuarangia MacKinnon, 1982, Camya Hinz-Schallreuter, 1995, and Arhouriella Geyer and Streng, 1998 most probably belong to the class Bivalvia. Palaeoecologically, the Cambrian bivalves of the Western Perigondwanan shelf seem to occur in a relatively small window of low-energy, subtidal, open-marine, warm-water conditions on a muddy carbonate ramp or platform with reduced sedimentation rate. The frequently interpreted infaunal mode of life of Pojetaia and Fordilla is questioned by observations of similarly organized modern bivalves. The palaeogeographical distribution of Pojetaia and Fordilla is discussed with respect to their early ontogeny and to differences in the recent state of knowledge on shelly fossils from Cambrian carbonate successions of Perigondwana.     

Rocky-shore unconformities marking the base of Badenian (Middle Miocene) transgressions on Mt. Medvednica basement (North Croatian Basin,Central Paratethys)

Badenian (Middle Miocene) transgressive deepening-upward successions located in the NE part of Mt. Medvednica (North Croatian Basin, Pannonian Basin System) unconformably overlie Mesozoic basement. Triassic and Upper Cretaceous limestone pebbles, cobbles, and boulders of the Badenian basal conglomerates display abundant in situ bivalve borings of Gastrochaenolites and sponge borings of Entobia. This Gastrochaenolites-Entobia ichnoassemblage is related to the Entobia subichnofacies of the Trypanites ichnofacies, characterizing littoral rocky-shore environments (wave-cut platforms and marine transgressive surfaces with a low or null rate of sedimentation). Gastrochaenolites torpedo, Gastrochaenolites lapidicus, and Entobia recorded in Badenian basal conglomerates (compared with modern Northern Adriatic rocky-shore environments), enabled more precise palaeoenvironmental interpretations. The occurrence of G. torpedo (produced by lithophaginid bivalves) on all sides of individual limestone lithoclasts in the Gornje Ore?je basal conglomerate, coupled with truncation of the formation (possibly indicating multiphase colonization), reflect gravel transport, roll-over, overturning and erosion by wave action in high-energy rocky-shore settings. Gornje Psarjevo-2 basal conglomerate boulders were probably not subjected to significant movement and abrasion, as suggested by good preservation of both G. lapidicus (potentially produced by gastrochaenid bivalves), associated G. torpedo, as well as abundant shallow Entobia borings. The Badenian Gastrochaenolites-Entobia ichnoassemblage also could be the result of a composite development. However, direct cross-cutting relationships between G. torpedo and G. lapidicus and/or Entobia were rarely observed. In addition, Badenian boring tracemakers might have coexisted at the same water depth. Northeast Mt. Medvednica Badenian successions probably formed during different Central Paratethys transgressive pulses (NN5 and NN6 Zones). However, exact timing of Badenian transgressions, stratigraphic correlations and tectono-eustatic implications are unresolved, due to sparsely integrated biostratigraphic and high-precision geochronological studies of Early–Middle Miocene North Croatian Basin deposits and due to the absence of a uniform biostratigraphic zonation and regional chronostratigraphic division of Central Paratethys.     

Cytogenetic differentiation of natural populations of <Emphasis Type="Italic">Chironomus obtusidens</Emphasis> (Diptera,Chironomidae)

The cytogenetic structure of Siberian and European populations of Chironomus obtusidens Goetgh. was studied. The clear differentiation of these populations was revealed using quantitative analysis of sets and frequencies of inversion banding sequences. The Siberian populations were found to have six new inversion sequences, and the alternative obtG2 sequence dominated instead of the main obtG1 sequence typical of European populations. In general, chromosomal polymorphism was 3–4 times higher in the Siberian populations. Therefore, the cytogenetic distances (Dcg) between the Siberian and European populations were higher (Dcg 0.059–0.097) than Dcg between the populations in each of the geographic zones investigated (Dcg 0–0.015). The NJ phylogenetic tree constructed for the chromosomal evolution of the genus Chironomus demonstrates that Chironomus obtusidens is the most divergent member among Palaearctic species of the obtusidens group. In addition, it is closer related to the Nearctic Ch. decorus group.     

Trilobites of the suborder Eodiscina from the Lower Cambrian of the northeastern Siberian platform (Khorbosuonka River section)

Trilobites of the suborder Eodiscina from the Lower Cambrian section of the Khorbosuonka River (Siberian Platform, Olenek Uplift) are studied. The stratigraphic distribution of these forms in the section is shown Two new species, Hebediscus sublongus sp. nov. and Korobovia khorbosuonica sp. nov., are described. This is the first occurrence of the genus Korobovia on the Siberian Platform. The new record provides additional data on morphology and expands the paleogeographic range of the genera represented by the newly described species.     

New and rare snailfishes (Liparidae,Scorpaeniformes) with the description of four new species from the Southern Hemisphere and tropical east Pacific

New and rare liparid fishes (Liparidae, Scorpaeniformes) are found and described. Careproctus armatus Andriashev, 1991 sampled off the South Sandwich Islands (at a depth 2281–2369 m); it is the second record of the species. Four species are collected in the vicinity of the South Shetland Islands: Careproctus parini Andriashev et Prirodina, 1990 (off King George Island, 573–861 m), Paraliparis meganchus Andriashev, 1982 (off Elephant Island, 559 m), P. monoporus Andriashev et Neyelov, 1979 (off Elephant Island, 559 m) and Paraliparis specimens, most similar to P. tompkinsae Andriashev, 1992 (off King George Island, 766–861 m). Paraliparis charcoti Duhamel, 1992 recorded at the eastern part of the Weddell Sea (475–633 m). Paraliparis, most similar to P. tetrapteryx Andriashev et Neelov, 1979, found in the Southwestern Atlantic (1200 m). Four new species are described. Paraliparis porcus sp. nov. based on one male SL 85 mm from off the South Shetland Islands (Elephant Island, 332–374 m). Paraliparis acutidens sp. nov. described from the juvenile SL 115 mm, sampled in the western part of the Scotia Sea (3721–3723 m). Paraliparis kocki sp. nov. known from 3 adults caught in the depression of the Bransfield Strait (1914–1920 m), isolated from the Weddell Sea by shallower waters. The only specimen of the Paraliparis mexicanus sp. nov. collected in the tropical Pacific off Mexico at depth not more than 900 m.     

On Frasnian ammonoids of the New Siberian Islands

Ammonoids from the basal beds of the Nerpalakh Formation (Lower Frasnian) of Belkovsky Island (New Siberian Archipelago) are systematically studied. Taxonomically, the assemblage studied (Manticoceras insulare sp. nov., Tornoceras typum (Sandberger, 1851), and T. contractum Glenister, 1958) is similar to the Early Frasnian ammonoid assemblage of South Timan, from which its is distinguished by the absence of the genera Timanites and Komioceras. The same beds contain conodonts of the Palmatolepis transitans Zone (= MN 4 Zone of the Montagne Noire standard succession), which allow the correlation of the beds studied with the Timanites keyserlingi and Komioceras stuckenbergi ammonoid zones of South Timan. The Early Frasnian ammonoids could supposedly have entered the region of the New Siberian Archipelago from the southwest at the time of a major transgression, which facilitated the distribution of the genera Manticoceras and Tornoceras. A new species of the genus Manticoceras is described.     

Jurassic lacewings (Insecta: Neuroptera) of Western Siberia

A lacewing assemblage from the Middle Jurassic of the West Siberian Kubekovo locality, the only know Jurassic lacewing fauna of Russia, is discussed. One new genus and two new species of Osmylidae from Kubekovo, Kubekius multiramosus gen. et sp. nov. and Epiosmylus longus sp. nov. are described. Thaumatomerobius mirabilis Ponomarenko, 1985 is transferred to the family Saucrosmylidae, which has only been recorded in the Middle Jurassic of Daohugou.     

Shell chirality in Cambrian gastropods and sinistral members of the genus <Emphasis Type="Italic">Aldanella</Emphasis> Vostokova, 1962

Shell chirality among Cambrian gastropods is discussed. It is demonstrated that the earliest members of the class include chiral aberrations with abnormal opposite coiling of the shell. It is assumed that, in Cambrian gastropods, speciation could have occurred by mutation in the locus determining the chirality, as is proposed for extant gastropods. In contrast to modern gastropods, the existence of chiral morphs within single species has not been recorded in Cambrian mollusks, whereas the presence of chiral twin species is possible. The systematic position of sinistral representatives of the genus Aldanella Vostokova, 1962 is considered. Aldanella golubevi sp. nov. with sinistral shell is described from the base of the Tommotian Stage of the Anabar Region. Aberrant sinistral specimens of the normally dextral species Aldanella utchurica Missarzhevsky in Rozanov et al., 1969 and Pelagiella adunca Missarzhevsky in Rozanov et al., 1969 are figured.     

<Emphasis Type="Italic">Pelekysgnathus jeppssoni</Emphasis>, a new conodont species from the Eifelian Stage of the Bryansk Region,Russia

Distribution of the Devonian conodont genus Pelekysgnathus is considered. A new species, P. jeppssoni sp. nov. from the Mosolovian Regional Stage (Middle Devonian, Eifelian) of the Voronezh Anteclise is described.     

New Middle Devonian conodont data from the Dong Van area,NE Vietnam (South China Terrane)

Middle Devonian conodonts from the Si Phai section in NE Vietnam are described. The section ranges from the Middle Devonian ensensis to timorensis conodont zones to the Late Devonian rhomboidea conodont Zone. A rich overall assemblage is described, including 27 taxa of species or subspecies rank and 11 taxa described in an open nomenclature. Among the dominant Polygnathus forms, four new taxa are described: Polygnathus linguiformis saharicus subsp. nov., Polygnathus linguiformis vietnamicus subsp. nov., Polygnathus rhenanus siphai subsp. nov., and Polygnathus xylus bacbo subsp. nov. Conodont assemblages are attributed to polygnathid, polygnathid-klapperinid, and klapperinid conodont biofacies representing hemipelagic to pelagic environments. The klapperinid biofacies, unreported in the previous literature, are here attributed to offshore areas of the external shelf. The taxonomic compositions of the studied conodont assemblages, as well as their CAI characteristics (CAI 4–5), suggest a palaeogeographic affinity of the studied strata to the Chinese Devonian Guangxi Basin, and the South China Terrane in general. Furthermore, the conodont biofacies and the palaeogeographic distribution of the fauna are discussed.     

Pollen of Castaneoideae (Fagaceae) from the Holocene sediments of the Sea of Japan

Fossil pollen grains of Castaneoideae from Holocene sediments from the southern Sea of Japan (J-3) at a depth of 200–202, 165–167, and 120–122 cm were studied with a scanning electron microscope. Pollen of some extant species of Castaneoideae, native to the region (Castanopsis cuspidata, C. sclerophylla, and Lithocarpus glaber) were also studied. As a result, four types of fossil pollen grains were revealed; type I is identified to species as Castanopsis cuspidata, type II is referred to the genus Castanopsis, type III is assigned to the genus Lithocarpus, and type IV is only identifined to subfamily (Castaneoideae type).     

Redescription of a <Emphasis Type="Italic">Lotagnostus</Emphasis>–<Emphasis Type="Italic">Mendoparabolina</Emphasis> faunule (Trilobita; late Furongian) from Quebrada San Isidro,Precordillera of Mendoza,Argentina

Lotagnostus is a biostratigraphically important late Furongian (late Cambrian) agnostoid trilobite whose interspecific and intraspecific variability is currently under discussion. In this context, type material of Lotagnostus atenuatus Rusconi, from an open-marine black limestone allochthonous block (La Cruz Olistolith) of Quebrada San Isidro, Precordillera of Mendoza, western Argentina, is revised herein. It includes several three-dimensionally preserved sclerites, allowing for an emended diagnosis of this species and comprehensive comparisons with other forms of Lotagnostus. Although to date L. atenuatus can be identified with confidence only at Quebrada San Isidro, it strongly resembles fragmentary material of Lotagnostus sp. indet., from late Furongian dysoxic upper slope facies of the Central Appalachians in eastern North America. The olenid Mendoparabolina brevicauda Rusconi, which is recorded in association with L. atenuatus, is also redescribed here. Mendoparabolina is closely allied with Wujiajiania Lu and Lin and Bienvillia Clark, differing by having a proportionately long and transversely bilobate pygidium with a posteriorly truncate axis and a postaxial median ridge.     

Vertebrae of sea snakes from the Eocene of the Crimea

A sea snake vertebra from the Middle Eocene (Kuma Horizon) of the vicinity of the town of Bakhchisarai (Crimea) is referred to Palaeophis nessovi Averianov, 1997, which was previously recorded in the Middle and Upper Eocene of northern and western Kazakhstan. P. udovichenkoi Averianov, 1997 described from the Crimea based on the material from the Prolom locality (Bartonian-Priabonian?) is a junior subjective synonym of P. nessovi. A vertebra from the Belaya Skala locality (Middle Eocene, outskirts of the town of Belogorsk) is determined as Palaeophis sp.     

Cystoporida (Bryozoa) from the Emsian Stage (Lower Devonian) of the Salair Ridge and Gorny and Rudny Altai

Eight bryozoan species of the order Cystoporida are described from the Emsian Stage of the Lower Devonian in the western Altai-Sayan Folded Area. Five of them are new species: Fistulipora salairiensis sp. nov., Fistuliramus fasciculus sp. nov., Fistuliphragma sibirica sp. nov., F. moniliformis sp. nov., and Fistulocladia cincinnata sp. nov. The others belong to the genera Ganiella, Physallidopora, and Fistuliporidra. Most of the cystoporid species studied from the Emsian Stage in the Altai-Sayan Folded Area are widespread laterally. Six cystoporid species have a narrow stratigraphic range and are, therefore, characteristic species of the bryozoan biostratigraphic zones of this region. The species of Physallidopora cantabrica Ernst et Buttler and Fistuliporidra hibera Ernst et Buttler, for the first time encountered in the Emsian of Gorny and Rudny Altai, were previously described from coeval deposits in northwestern Spain.     

Morphological and molecular investigations of <Emphasis Type="Italic">Gagea</Emphasis> (Liliaceae) in southeastern Kazakhstan with special reference to putative altitudinal hybrid zones

The most important center of speciation in the genus Gagea is thought to be in Central Asia. Here, we focus on species diversity in southeastern Kazakhstan (around Almaty, Ili-Alatau range of the Western Tian-Shan mountains). We studied an elevational transect, reaching from lowland steppes to the alpine zone (500–2750 m a. s. l.), and carried out detailed morphological and molecular investigations for populations of Gagea spp. Nine species were identified in different altitudinal zones; one of these (Gagea almaatensis) is described as new to science. We could detect two altitudinal contact zones between closely related species: G. filiformis and G. granulosa (sect. Minimae), and G. almaatensis and G. kuraminica (sect. Gagea). Morphological and molecular investigations (ITS data and cpDNA networks) indicate ongoing hybridization of co-occurring G. filiformis into G. granulosa and putative bidirectional hybridization events between G. almaatensis and G. kuraminica.     

Ammonites of Tethyan Origin in the Ryazanian Stage of the Russian Platform: Genera <Emphasis Type="Italic">Transcaspiites</Emphasis> Luppov and <Emphasis Type="Italic">Karasyazites</Emphasis> gen. nov.

This paper presents the results of the study of ammonites of the family Himalayitidae from the Surites spasskensis Zone of the Ryazanian Stage of Central Russia. The new taxa Transcaspiites tscheffkini sp. nov., T. transitionis sp. nov., and Karasyazites gen. nov., with the type species Subalpinites bajarunasi Luppov, are described. The hypothesis that Transcaspiites Luppov originated from the genus Riasanites Spath is proposed. The analysis of the taxonomic composition of ammonites allows the Neocosmoceras–Septaliphoria semenovi regional zone of Mangyshlak to be correlated with the Spasskensis zone of the standard scale of the Ryazanian Stage.     

New multiarmed crinoids of the family Catillocrinidae from the Lower Permian of the Fore-Urals

New Catillocrinidae Allocatillocrinus rarus sp. nov., with a previously unknown tegmenal structure, Paracatillocrinus shamovi sp. nov., and P. shakhtauensis sp. nov., with an unusual relative position of the crown and stem are described from the Artinskian Stage (Lower Permian) of the western slope of the Middle and Southern Ural Mountains (Boets, Krasnoufimsk, and Shakh-Tau localities). The genus Allocatillocrinus has not previously been recorded from the Permian, while Paracatillocrinus has only previously been reported from the Upper Permian of Timor Island.