Lapworthellids and other skeletonised microfossils from the Cambrian Stage 3 of the northern Montagne Noire,southern France

The Montagne Noire (southern France) possesses one of the most complete Cambrian successions in the western peri-Gondwana margin and might provide a good stratigraphic reference for both regional charts and international correlations. However, to date, the lower Cambrian succession of the northern Montagne Noire has been supposed to be devoid of biostratigraphically significant fossils. The complex tectonostratigraphic framework of the area (a range divided into Axial Zone, northern and southern Montagne Noire) exacerbated problems related to regional correlations and palaeogeographic reconstructions. As a result, the chronostratigraphic context of the lower Cambrian of northern Montagne Noire is still uncertain and stratigraphic reports have broadly relied on putative lithostratigraphic correlations with the southern Montagne Noire. The purpose of this study is to characterise, for the first time, the fossil record of carbonate beds and lenses of the northern Montagne Noire occurring at the top of the siliciclastic-dominated Marcory Formation, in order to provide regional bio- and chronostratigraphic constraints on lower Cambrian strata. Moreover, this study is aimed at improving international chronostratigraphic correlation. Carbonate beds and lenses cropping out along the Orque Cliff, in the Mélagues thrust slice, were investigated. They yielded a faunal assemblage constituted of molluscs (Igorella cf. ungulata and Igorella moncereti n. sp.), hyoliths (Conotheca brevica), chancelloriids (Archiasterella cf. pentactina and Allonnia sp.) and tommotiids (Lapworthella rete). L. rete is recorded in upper Meishucunian (Cambrian Stage 3) strata of the Yangtze Platform (South China) where it is used as index fossil of the Cambrian Stage 3 Sinosachites flabelliformis–Tannuolina zhangwentangi Assemblage Zone. Therefore, the presence of this tommotiid provides evidence that the studied carbonate beds and lenses are Cambrian Age 3 (Atdabanian according to the Siberian chart). The upper part of the Marcory Formation in the Mélagues slice, dated as Cambrian Stage 3, might represent a lateral equivalent of the mixed (carbonate-siliciclastic) Pardailhan Formation defined in the southern Montagne Noire.     

Pelecyogyra (Mollusca) from the Early Ordovician of the Montagne Noire,France

A new occurrence of the onychochilid mollusc Pelecyogyra is reported from the late Floian Landeyran Formation (Apatokephalus incisus Biozone) in the Montagne Noire, southern France, where it is associated with the two tergomyans Carcassonnella courtessolei and Thoralispira laevis, and a mollusc indet. With a low cap-shaped shell. The Montagne Noire specimens compare morphologically with Pelecyogyra fezouataensis from the late Tremadocian Fezouata Formation (Araneograptus murrayi Biozone) in Morocco and are tentatively referred to this species. Each occurrence of Pelecyogyra is from one or two localities only, but separated in time. They differ further in the deeper facies, association with Carcassonnella and Thoralispira, and non-gregarious occurrence in Montagne Noire compared to the shallower facies, lack of other molluscs and gregarious occurrence in the Fezouata Formation. In the Lower Ordovician, Pelecyogyra, Carcassonnella courtessolei, the rare C. vizcainoi and Thoralispira laevis are taxa that occur only in Montage Noire and the Anti-Atlas, while Lesueurilla prima also occurs in the Prague basin of the Czech Republic. Contrary to other faunal elements, like echinoderms and trilobites, these genera seem to have a wide environmental tolerance and are long ranging taxa. The main occurrence of the three key taxa Carcassonnella, Thoralispira and Lesueurilla in the Montagne Noire is in the lower part of the La Maurerie Formation (Taihungshania miqueli acme Zone), while the same taxa appear just slightly later in Morocco (?Cymatograptus protobalticus Biozone). Migration to the Anti-Atlas during the early Floian seems to have been possible during a period of general faunal exchange. Pelecyogyra may either have migrated from the Anti-Atlas to Montagne Noire during the same interval or possibly during the late Floian as indicated by shared faunal elements between these two regions at that time.     

Gigantoproductid and allied productid brachiopods from the “Calcaires à Productus” (late Viséan-Serpukhovian; Montagne Noire,southern France): Taxonomy and palaeobiogeographical position in the Palaeotethys

The “Calcaires à Productus” or “Calcaires à Productus giganteus” on the southern slope of the Montagne Noire (Hérault, France) consist of numerous isolated olistolitic limestone blocks, generally transported by gravitational flows into siliciclastic basinal deposits. The present paper is the first systematic monographic study of gigantoproductids, semiplanids, and some other large-sized productid brachiopods from the upper Viséan to Serpukhovian strata of the Montagne Noire. Gigantoproductids are represented by abundant Datangia semiglobosa and Kansuella spp.; a single Globosoproductus specimen is described. The semiplanids are represented by Latiproductus aff. latissimus, L. latissimus complicatus and L. edelburgensis, and the linoproductids by Balakhonia aff. kokdscharensis. The Montagne Noire productid faunas are found in very different facies including shell beds and microbial mounds. They are most abundant in assemblages from agitated, shallow water environments with a firm substrate where rugose corals are rare or absent. The palaeobiogeographical relations to the other regions in the western Palaeotethys are often limited to taxa with an almost cosmopolitan character. Worth noting is the absence of Gigantoproductus sensu stricto in the Montagne Noire. This genus, and other brachiopod taxa, migrated probably during the late Serpukhovian into southern France. On a larger scale, the presence of Kansuella indicates faunal exchanges with the eastern Palaeotethys (South China) via a westward migration path along North China, the Central Asian Orogenic Belt and south-eastern Laurussia. The studied taxa, even at the genus level, did not migrate into North America even if the Alleghanian Isthmus was still open.     

Les Echinodermes Cincta du Cambriende la Montagne Noire (France)

Here is a revision of the Cincta Echinodermata, first in connection with stratigraphy bythe study of a series of organisms collected level by level in the Montagne Noire; secondly through the search of anatomical features characterizing genera and species. The first genera to appear is Decacystis, also known from Spain; Gyrocystis, not completely described, cannot be maintained; Trochocystis, from Bohemia, is missing. On the other hand, Sucocystis, Elliptocinctus (new genera for Tr. barrandei), Cephalocinctus, Cyclocinctus and Trochocinctus remain available and special to the Montagne Noire, except Cyclocinctus which is found also in Morocco.     

Some solenopleurine trilobites from the Languedocian (Late Mid Cambrian) of Western Europe

The solenopleurine trilobite genera Jincella and Liosolenopleura are revised herein. The species Jincella prantli, Jincella convexa nov. sp. and Liosolenopleura serventi occur in Languedocian (upper Middle Cambrian) rocks of the southern Montagne Noire (France), southwestern Sardinia (Italy), and the P?íbram-Jince and Skryje areas (Czech Republic). The correlation of their first appearances permits us to improve the Middle Cambrian biostratigraphic correlations in western and central Europe. At least 17 Middle Cambrian Bohemian species are already reported outside the Czech Republic, whose outcrops can be considered as a hinge in the correlations between southwestern Europe, Saxo-Thuringia, Avalonia and Baltica.     

Early Late Cambrian Trilobites OF Australo-Sinian Aspect From The Montagne Noire, Southern France

Ten species of Late Cambrian trilobites occur in a limestone lens at the base of the Val d'Homs Formation in the Cesse Brook section at Ferrals‐les‐Montagnes in the Montagne Noire. Associated in this lens are species referred to Ammagnostus (Ammagnostus), Kormagnostus?, Olentella, Stigmatoa, Shengia, Abharella, Proceratopyge, (Proceratopyge), ProchuangiaPalaeadotes and Paraacidaspis. Of these, Stigmatoa courtessolei and Paraacidaspis ultima are described as new species. The Ferrals fauna has a decidedly Australo‐Sinian palaeobiogeographical relationship, with the implication that previously developed models suggesting a high latitudinal position for southern France during the Late Cambrian should perhaps be revised. key words : Late Cambrian, trilobites, southern France, Ferrals‐les‐Montagnes, Montagne Noire, biostratigraphy, biogeography.     

Biostratigraphical precisions on the Early Serpukhovian (Late Mississippian), by means of a carbonate algal microflora (cyanobacteria, algae and pseudo-algae) from La Serre (Montagne Noire, France)

The microbial-dominated part of a Late Mississippian (Early Carboniferous) carbonate olistolite at La Serre (Montagne Noire, southern France) yielded interesting algae and pseudo-algae. The constituents are well known cyanobacteria (not described) and different representatives of poorly known or new species: cyanobacteria: Aphralysia capriorae, Hedstroemia (?) serrana n. sp., Dasycladales: Paraepimastopora sp., Nanopora sp., Cabrieropora pokornyi and E. occitanica, Anatoliporaceae: Richella incrustata, Caulerpales: Poncetellina (?) sp., questionable Archaeolithophyllaceae: Hortonella sp., Archaeolithophyllaceae: Neoprincipia with Neopricipia fluegeli, Neoprincipia petschoriaeformis n. sp., Neoprincipia claviformis n. sp. and Archaeolithophyllum ex gr. lamellosum; pseudo-algae Aoujgaliida: Stacheoidella spissa, Ungdarella uralica, and Fasciellidae: Fasciella and Praedonezella, with both polymorph species: Fasciella kizilia, and Praedonezella ex gr. cespeformis. This carbonate microflora is dated as Early Serpukhovian (Pendleian) by its association with the foraminifera Janichewskina, “Biseriella” and “Warnantella”. This dating is confirmed by the little more advanced algal assemblage, compared to the Latest Visean (Brigantian) assemblages from Montagne Noire (e.g. Japhet, Castelsec), and more primitive than the Late Serpukhovian (Arnsbergian) of Ardengost (Pyrenees). The importance of the calcifoliid pseudo-algae—Fasciella, Praedonezella, and Calcifolium (although this latter is locally lacking)—is suggested for the biozonation of the Visean/Serpukhovian boundary.     

A NEW EARLY ORDOVICIAN CONODONT GENUS FROM THE SOUTHERN MONTAGNE NOIRE, FRANCE

Abstract:  Two species of a new Tremadocian (Early Ordovician) conodont genus from the Saint Chinian Formation of the southern Montagne Noire, France, are erected: Hammannodus sarae gen. et sp. nov. and Hammannodus juliae gen. et sp. nov. They were found within a single storm-induced limestone nodule interbedded with offshore shales belonging to the regional Shumardia ( C .) pusilla (trilobite) Biozone, and to the Paltodus deltifer deltifer (conodont) Subzone. This conodont record is associated with the episodic development of carbonate productivity in temperate waters of the Montagne Noire platform, a process absent in neighbouring platforms of north-west Gondwana. The apparatus is composed of five coniform pyramidal elements occupying P and S positions and one bicostate element in the M position, having three or two sharp costae, respectively, with a subtriangular basal outline.     

Deux Stylophora (Homalozoa,Echinodermata) nouveaux pour l’Ordovicien inférieur de la Montagne Noire (France Méridionale)

Two stylophoran carpoids from the Lower Ordovician (Arenig) of the Montagne Noire (France) are described. One of them,Nanocarpus dolambii n. g., n. sp., is a cornute which shares many features withAmygdalotheca griffei, Reticulocarpos hanusi andProkopicystis mergli; it is mainly characterized by its very small size, the shortness of its aulacophore, and the presence of non-plated integuments on both faces of the theca. The other one is a mitrate very close to, if not identical with,Lagynocystis pyramidalis from the Llanvirn of Bohemia and the Llanvirn-Llandeilo of the Armorican Massive (France).     

Evolution de l’il et h’t’rochronie chez les trilobites ordoviciensormathops delo 1935 ettoletanaspis rabano 1989 (dalmanitidae,zeliszkellinae)

Ormathops species of Arenig (Fennian) and Llanvirn age(O. llanvirnensis, O. atava, O. clariondi) possess visual surfaces characterized by irregularities in the distribution of lenses. Yet, at early Caradoc time, the eyes ofOrmathops hupei are perfectly schizochroal. From the Arenig to the Lower Llanvirn, the same evolution can be noticed in the genusToletanaspis: the eyes ofT. borni andT. courtessolei n. sp., both from the Whitlandian of the Montagne Noire (southern France), show irregular lens-packing whereasT. trivignoi of Lower Llanvirn age has a schizochroal pattern of lenses. InOrmathops andToletanaspis, the schizochroal condition has developed independently from a primitive lens-packing system, probably through a paedomorphic (neotenic) “process”. Résumé: Les espèces d’Ormathops d’âges Arenig (Fennien) et Llanvirn (O.llanvirnensis, O. atava,O. clariondi) possèdent des surfaces visuelles caractérisées par des irrégularités de distribution des lentilles. Toutefois, au début du Caradoc, les yeuxd’Ormathops hupei sont parfaitement schizochroaux. De l’Arenig au Llanvirn Inférieur, la même évolution s’observe chez le genreToletanaspis: les yeux deT. borni etT. courtessolei n. sp., toutes deux du Whitlandien de la Montagne Noire (France méridionale), montrent une distribution irrégulière des lentilles tandis queT. trivignoi d’âge Llanvirn Inférieur présente des surfaces visuelles schizochroales. ChezOrmathops etToletanaspis, l’?il schizochroal s’est formé indépendamment à partir d’une surface visuelle primitive à lentilles irrégulièrement réparties, et ceci probablement par paedomorphose (néoténie).     

Siphonodella leiosa (Conodonta), a new unornamented species from the Tournaisian (lower Carboniferous) of Puech de la Suque (Montagne Noire,France)

A new conodont species, Siphonodella leiosa, is described from the lower Carboniferous pelagic limestones of the Montagne Noire (France), deposited in North Gondwana on a outer platform environment. Specimens were obtained from one level dated to the Siphonodella jii conodont Zone. The major difference from other siphonodellid conodonts known in this area is that the elements of this new species have a practically entirely smooth and unornamented platform, apart from the development of one or two low rostral ridge-like nodes. Similar morphologies were generally observed in shallow marine deposits of the same time frame from China, Russia and East and Central European areas. The new discovery reinforces the idea that ornamentation of siphonodellids is not only related to bathymetry, but that temperature could play an important role in the diversification and radiation of unornamented species during the Siphonodella jii conodont Zone.     

Early Cambrian organophosphatic brachiopods from the Xinji Formation,at Shuiyu section,Shanxi Province,North China

Abundant and diverse small shelly fossils have been reported from Cambrian Series 2 in North China, but the co-occurring brachiopods are still poorly known. Herein, we describe seven genera, five species and two undetermined species of organophosphatic brachiopods including one new genus and new species from the lower Cambrian Xinji Formation at Shuiyu section, located on the southern margin of North China Platform. The brachiopod assemblage comprises one mickwitziid (stem group brachiopoda), Paramickwitzia boreussinaensis n. gen. n. sp., a paterinide, Askepasma toddense Laurie, 1986, an acrotretoid, Eohadrotreta cf. zhenbaensis Li and Holmer, 2004, a botsfordiid, Schizopholis yorkensis (Holmer and Ushatinskaya in Gravestock et al., 2001) and three linguloids, Spinobolus sp., Eodicellomus cf. elkaniiformis Holmer and Ushatinskaya in Gravestock et al., 2001 and Eoobolus sp. This brachiopod assemblage suggests a late Age 3 to early Age 4 for the Xinji Formation and reveals a remarkably strong connection with coeval faunas from East Gondwana, particularly the Hawker Group in South Australia. The high degree of similarity (even at species level) further supports a close palaeogeographic position between the North China Platform and Australian East Gondwana during the early Cambrian as indicated by small shelly fossil data.     

A re-evaluation ofBlayacina Cobbold 1932 andThoralaspis Hupe 1953 (Trilobita: Redlichiida)

The monotypic trilobite generaBlayacina andThoralaspis from the late Early Cambrian of the Montagne Noire, Southern France, are revised. Restudy of the type specimens and of new material from the type locality and stratum as well as morphometric measurements strongly support the assumption that both taxa are identical and that morphologic as well as taxonomic differences resulted from tectonic distortion. Thus,Thoralaspis thorali has to be regarded as a subjective junior synonym ofBlayacina miqueli andThoralaspis as a junior synonym ofBlayacina. Its systematic position as a morphologic group aroundLusatiops within the Ellipsocephalidae-Protoleninae is confirmed.     

Late Viséan–Serpukhovian foraminifers in the Montagne Noire (France): Biostratigraphic revision and correlation with the Russian substages

The “calcaires à Productus” of the Montagne Noire (Aude-Hérault, southern France) are carbonate lenses embedded within a thick Carboniferous siliciclastic complex. Foraminiferal assemblages in some of the larger carbonate lenses are typically representative of the late Viséan and Serpukhovian. Eleven new species of foraminifers are described: Hemidiscopsis variabilis, H. pilleae, Planohowchinia rara, P. redondensis, Spireitlina minima, Rectoendothyra japhetensis, Mikhailovella enormis, Cribrospira? perretae, Pojarkovella occidentalis, Parabiseriella vailhanensis, and Biseriella delicata. Eight foraminiferal biozones are defined; they are based on the first occurrence of some taxa, and could be used for other regions of southern France (e.g., Mouthoumet and the Pyrenees). These biozones are informally named as A to H. Due to the problems with classical biozonations and substages in northern England as well as Belgium and northern France, the biozones established herein are mostly compared with the Russian standard substages. Thus, biozones A and B are correlated with the Mikhailovian, corresponding to the latest Asbian and earliest Brigantian in western Europe; biozones C, D and E are correlated with the Venevian, equivalent to the upper part of the early Brigantian in western Europe. Therefore, biozones A–E form part of the late and latest Viséan. The stratigraphically younger biozones F, G and H contain foraminiferal assemblages correlated with the Tarusian, Steshevian and Protvian, respectively.     

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.     

A new problematic Early Ordovician univalve mollusc from France

Lamaureriella vizcainoi gen. et sp. nov., from the Montagne Noire region of southern France, is a coiled, laterally compressed, bilaterally symmetrical mollusc in which prominent folds in the apertural margin produce a characteristic spiral plication across each lateral surface. Similar plications are present in technophorid rostroconchs but the prominent coiling and lack of a pegma suggest that Lamaureriella is a helcionelloid. It is the second such genus described from Early Ordovician rocks.     

Family Dibrachicystidae (Echinodermata: Rhombifera) from the “Middle” Cambrian of the Barrandian area,Czech Republic

A slightly crushed but otherwise nearly complete specimen of the recently described rhombiferan echinoderm genus Vizcainoia Zamora and Smith, 2012 is documented from the “Middle” Cambrian Jince Formation of the P?íbram–Jince Basin of the Czech Republic. Isolated thecal plates, earlier determined as calyx plates of the eocrinoid Acanthocystites briareus Barrande, 1887 and/or as eocrinoid sp., occurring in diverse levels of the Jince Formation are reassigned to Dibrachicystidae gen. et sp. indet. Similarly, isolated thecal plates collected from the Buchava Formation of the Skryje–Tý?ovice Basin could be classified as Dibrachicystidae gen. et sp. indet. Specimens from the Barrandian area are the first records of the family Dibrachicystidae outside of southwestern Europe, of the family otherwise known only from the Languedocian of Montagne Noire of France and from the Caesaraugustian and Languedocian of Iberian Chains of northern Spain.     

Phyllocarid remains (Malacostraca, Crustacea) from the basal Famennian (Late Devonian) of the Montagne Noire (Southern France)

From the early Famennian of the Montagne Noire 19 different morphotypes of probably phyllocarid (Crustacea) affinities are described. Apart from formerly unknown enamel-like structures that veil the uppermost tips of the denticles on most of the gnathal lobe morphs, the stratigraphic implications concerning extinction behaviour across the Kellwasser mass extinction event and during early Famennian diversification are discussed. In addition, phyllocarids in the Famennian seem to form a useful stratigraphic tool for biostratigraphical correlation. Therefore, three basal Famennian phyllocarid assemblage zones are distinguished.      

Upper Devonian conodonts of northeastern European Russia

The conodont succession in the Upper Devonian facially different sections of northeastern European Russia (Chernyshev Ridge, Subpolar and Polar Urals, Pai-Khoi) are studied. The sections are subdivided and correlated taking into account the global standards for stages. The Frasnian Montagne Noire zonation (Klapper, 1989) is used for the first time for northeastern European Russia; the authors correlated this zonation with the scale of Ziegler and Sandberg (1990). Famennian deposits are subdivided using scale of Ziegler and Sandberg (1984) and miospore zonation. The age of local geological units (formations) is specified; the formations of different regions of northeastern European Russia are correlated to each other and to the regional subdivisions of EEP and Southern Urals. A total of 93 species of Ancyrodella, Mesotaxis, Palmatolepis, Polygnathus, and Zieglerina are described. Two new species Ctenopolygnathus parallelus sp. nov. and Polygnathus masonae sp. nov. are distinguished and five species are described in the open nomenclature. Special chapter is devoted to the phylomorphogenesis of Ancyrodella.