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Julien Denayer - One of the best experts on this subject based on the ideXlab platform.
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Taxonomy and evolution of late Tournaisian and Viséan (early Carboniferous) Heterostrotioninae (Rugosa, Anthozoa) from SE China
Journal of Systematic Palaeontology, 2020Co-Authors: Julien Denayer, Eddy Poty, Markus AretzAbstract:Colonial rugose corals with a heterocoral-like septal pattern are diverse and common in the Tournaisian–Visean (Mississippian) of South China. Numerous species were named in classical works but mos...
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Palaeoecology of the Upper Tournaisian (Mississippian) crinoidal limestones from South Belgium
Geologica Belgica, 2018Co-Authors: Laurent Debout, Julien DenayerAbstract:1. Introduction The Mississippian (Lower Carboniferous) and particularly the Tournaisian is known as the golden age of crinoids (Kammer & Ausich, 2006). In suitable settings, the crinoids lived in vast meadows that formed the carbonate rock through the accumulation of their skeletal elements and named regional encrinites (sensu Ausich, 1997). Tournaisian encrinites are wide developed all over the world with renown examples from Ireland (Waters & Sevastopulo, 1984), N America (Ausich, 1999a,b), S China (Chen & Yao, 1993), Iran (Webster et al., 2003), etc. The expansion of crinoids during the Tournaisian is interpreted as a recovery phase following the Late Devonian extinctions, as it induced a rapid re-colonisation of the ecological niches by crinoids and then a rapid evolution (McGhee, 1996). The autoecology of crinoids is relatively well understood (Ausich & Bottjer, 1982, 2007; Ausich & Simms, 1999; Ausich et al., 1999a) in contrast to their synecology (i.e. interactions with the environment and with other organisms) despite their ability to shape their environment. In South Belgium, Tournaisian encrinites are abundant and locally called “Petit Granit” where quarried as cut stones for building and carving purposes. Several units were – and still are – intensively quarried for these purposes: the Hastiere Formation (Fm), Landelies Fm, Ourthe Fm, Flemalle Membre (Mbr) and Soignies Mbr. The most valuable and renowned are the encrinites of the Ourthe Fm in the Condroz area (cen
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rugose corals at the Tournaisian visean transition in the central taurides s turkey palaeobiogeography and palaeoceanography of the asian gondwana margin
Journal of Asian Earth Sciences, 2015Co-Authors: Julien DenayerAbstract:Abstract This paper gives the first taxonomic description of the Upper Tournaisian–Lower Visean rugose coral fauna of the Yaricak Formation (Aladag Unit, Central Taurides, South Turkey). Fifteen species belonging to twelve genera were identified, one species is newly described: Eokoninckocarinia gemmina . The corals are stratigraphically distributed in four assemblages. The two typical assemblages of the Upper Tournaisian are composed of widely distributed taxa ( Uralinia , Caninia , Proheterelasma , Zaphrentites ). The assemblage crossing the Tournaisian–Visean boundary is characterized by Eurasian and cosmopolitan and widely distributed taxa ( Calmiussiphyllum , Siphonophyllia , Bifossularia Amygdalophyllum , Caninophyllum , Keyserlingophyllum ) and Asian taxa ( Kueichouphyllum ). The youngest assemblage, dominated by Eokoninckocarinia gemmina sp. nov., has yielded foraminifers Moliniacian (Lower Visean) in age. These assemblages form a low diversity level-bottom community which is typical of the South Palaeotethys ‘ Kueichouphyllum Zone’ extending along the Asian margin of Gondwana (Cimmerian Terrane) during Lower Carboniferous times. As in the other Cimmerian blocks, all the corals are solitary and colonial taxa are virtually absent. This absence is tentatively explained by the high palaeolatitude (c. 50°S) position of the Cimmerian Terrane in the southern part of the Palaeotethys Ocean for this time slice. A cold-water palaeo-current running eastward along the Gondwana margin might also be considered as it possibly could explain the wide distribution of the Kueichouphyllum fauna, restricted east of Africa in the southern coast of the Palaeotethys. Palaeoceanography, palaeoclimate and facies issues are discussed as possible causes of the diversity gradient observed between the eastern (Australia, Malaya) and the western (North Africa) margin of the Gondwana.
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Rugose corals at the Tournaisian–Viséan transition in the Central Taurides (S Turkey) – Palaeobiogeography and palaeoceanography of the Asian Gondwana margin
Journal of Asian Earth Sciences, 2015Co-Authors: Julien DenayerAbstract:Abstract This paper gives the first taxonomic description of the Upper Tournaisian–Lower Visean rugose coral fauna of the Yaricak Formation (Aladag Unit, Central Taurides, South Turkey). Fifteen species belonging to twelve genera were identified, one species is newly described: Eokoninckocarinia gemmina . The corals are stratigraphically distributed in four assemblages. The two typical assemblages of the Upper Tournaisian are composed of widely distributed taxa ( Uralinia , Caninia , Proheterelasma , Zaphrentites ). The assemblage crossing the Tournaisian–Visean boundary is characterized by Eurasian and cosmopolitan and widely distributed taxa ( Calmiussiphyllum , Siphonophyllia , Bifossularia Amygdalophyllum , Caninophyllum , Keyserlingophyllum ) and Asian taxa ( Kueichouphyllum ). The youngest assemblage, dominated by Eokoninckocarinia gemmina sp. nov., has yielded foraminifers Moliniacian (Lower Visean) in age. These assemblages form a low diversity level-bottom community which is typical of the South Palaeotethys ‘ Kueichouphyllum Zone’ extending along the Asian margin of Gondwana (Cimmerian Terrane) during Lower Carboniferous times. As in the other Cimmerian blocks, all the corals are solitary and colonial taxa are virtually absent. This absence is tentatively explained by the high palaeolatitude (c. 50°S) position of the Cimmerian Terrane in the southern part of the Palaeotethys Ocean for this time slice. A cold-water palaeo-current running eastward along the Gondwana margin might also be considered as it possibly could explain the wide distribution of the Kueichouphyllum fauna, restricted east of Africa in the southern coast of the Palaeotethys. Palaeoceanography, palaeoclimate and facies issues are discussed as possible causes of the diversity gradient observed between the eastern (Australia, Malaya) and the western (North Africa) margin of the Gondwana.
Zoya Tolokonnikova - One of the best experts on this subject based on the ideXlab platform.
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Palaeoecology of Famennian-Tournaisian (Late Devonian-Early Carboniferous) bryozoans from central and southern regions of Russia
Palaeobiodiversity and Palaeoenvironments, 2017Co-Authors: Zoya Tolokonnikova, Andrej ErnstAbstract:The palaeoecology of Famennian-Tournaisian (Late Devonian-Early Carboniferous) bryozoans from central and southern regions of Russia is analysed. Famennian-Tournaisian bryozoans associations of the Altai-Sayan Folded Area and the south-western region of the West-Siberian plate was a shallow-middle shelf according to our own and literature data. Robust branching-fenestrate-bilaminar bryozoan associations are found in locations of warm water, transitional low-high water energy, normal salinity and changing sedimentation rate. Bryozoan associations from South Urals and the central part of the Russian plate are characterised by a low number of species and specimens. Encrusting unilaminar and delicate branching growth habits are dominate in the Russian Plate and indicate an environmental setting in close proximity to strandline.
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palaeobiogeography and diversification of Tournaisian visean bryozoans lower middle mississippian carboniferous from eurasia
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Zoya Tolokonnikova, Andrej Ernst, Patrick Wyse N JacksonAbstract:Abstract The Mississippian represented the last diversification event of bryozoans in the Palaeozoic which affected all taxonomic levels. Within the borders of modern Eurasia Tournaisian–Visean bryozoans are known from 24 areas, with a total of 878 species in 180 genera. Palaeobiogeographical analysis is here made according to the stages and substages of the Tournaisian and Visean. Six characteristic species were identified for the lower Tournaisian which are distributed in more than one region of the continent, and for the upper Tournaisian there are two such species. Eleven species occur in the narrow stratigraphic interval of the lower Visean that display a wide geographic distribution within Eurasia, in the upper Visean there are 14 such species. Analysis of the generic composition showed the closest similarity between Tournaisian bryozoans of Kazakhstan, the Kuznetsk Basin and Eastern Transbaikalia. Significant similarity in the generic composition of Germany, Britain, Ireland and France is observed during the Visean. Two centres of radiation bryozoans were identified: «Eastern» and «Western».
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Palaeobiogeography and diversification of Tournaisian–Viséan bryozoans (lower–middle Mississippian, Carboniferous) from Eurasia
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Zoya Tolokonnikova, Andrej Ernst, Patrick N. Wyse JacksonAbstract:Abstract The Mississippian represented the last diversification event of bryozoans in the Palaeozoic which affected all taxonomic levels. Within the borders of modern Eurasia Tournaisian–Visean bryozoans are known from 24 areas, with a total of 878 species in 180 genera. Palaeobiogeographical analysis is here made according to the stages and substages of the Tournaisian and Visean. Six characteristic species were identified for the lower Tournaisian which are distributed in more than one region of the continent, and for the upper Tournaisian there are two such species. Eleven species occur in the narrow stratigraphic interval of the lower Visean that display a wide geographic distribution within Eurasia, in the upper Visean there are 14 such species. Analysis of the generic composition showed the closest similarity between Tournaisian bryozoans of Kazakhstan, the Kuznetsk Basin and Eastern Transbaikalia. Significant similarity in the generic composition of Germany, Britain, Ireland and France is observed during the Visean. Two centres of radiation bryozoans were identified: «Eastern» and «Western».
Andrej Ernst - One of the best experts on this subject based on the ideXlab platform.
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Palaeoecology of Famennian-Tournaisian (Late Devonian-Early Carboniferous) bryozoans from central and southern regions of Russia
Palaeobiodiversity and Palaeoenvironments, 2017Co-Authors: Zoya Tolokonnikova, Andrej ErnstAbstract:The palaeoecology of Famennian-Tournaisian (Late Devonian-Early Carboniferous) bryozoans from central and southern regions of Russia is analysed. Famennian-Tournaisian bryozoans associations of the Altai-Sayan Folded Area and the south-western region of the West-Siberian plate was a shallow-middle shelf according to our own and literature data. Robust branching-fenestrate-bilaminar bryozoan associations are found in locations of warm water, transitional low-high water energy, normal salinity and changing sedimentation rate. Bryozoan associations from South Urals and the central part of the Russian plate are characterised by a low number of species and specimens. Encrusting unilaminar and delicate branching growth habits are dominate in the Russian Plate and indicate an environmental setting in close proximity to strandline.
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palaeobiogeography and diversification of Tournaisian visean bryozoans lower middle mississippian carboniferous from eurasia
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Zoya Tolokonnikova, Andrej Ernst, Patrick Wyse N JacksonAbstract:Abstract The Mississippian represented the last diversification event of bryozoans in the Palaeozoic which affected all taxonomic levels. Within the borders of modern Eurasia Tournaisian–Visean bryozoans are known from 24 areas, with a total of 878 species in 180 genera. Palaeobiogeographical analysis is here made according to the stages and substages of the Tournaisian and Visean. Six characteristic species were identified for the lower Tournaisian which are distributed in more than one region of the continent, and for the upper Tournaisian there are two such species. Eleven species occur in the narrow stratigraphic interval of the lower Visean that display a wide geographic distribution within Eurasia, in the upper Visean there are 14 such species. Analysis of the generic composition showed the closest similarity between Tournaisian bryozoans of Kazakhstan, the Kuznetsk Basin and Eastern Transbaikalia. Significant similarity in the generic composition of Germany, Britain, Ireland and France is observed during the Visean. Two centres of radiation bryozoans were identified: «Eastern» and «Western».
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Palaeobiogeography and diversification of Tournaisian–Viséan bryozoans (lower–middle Mississippian, Carboniferous) from Eurasia
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Zoya Tolokonnikova, Andrej Ernst, Patrick N. Wyse JacksonAbstract:Abstract The Mississippian represented the last diversification event of bryozoans in the Palaeozoic which affected all taxonomic levels. Within the borders of modern Eurasia Tournaisian–Visean bryozoans are known from 24 areas, with a total of 878 species in 180 genera. Palaeobiogeographical analysis is here made according to the stages and substages of the Tournaisian and Visean. Six characteristic species were identified for the lower Tournaisian which are distributed in more than one region of the continent, and for the upper Tournaisian there are two such species. Eleven species occur in the narrow stratigraphic interval of the lower Visean that display a wide geographic distribution within Eurasia, in the upper Visean there are 14 such species. Analysis of the generic composition showed the closest similarity between Tournaisian bryozoans of Kazakhstan, the Kuznetsk Basin and Eastern Transbaikalia. Significant similarity in the generic composition of Germany, Britain, Ireland and France is observed during the Visean. Two centres of radiation bryozoans were identified: «Eastern» and «Western».
Jean Galtier - One of the best experts on this subject based on the ideXlab platform.
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Ahnetia, a new lignophyte stem from the Lower Carboniferous of southern Algeria
Review of Palaeobotany and Palynology, 2017Co-Authors: Anne-laure Decombeix, Jean GaltierAbstract:A new taxon of lignophyte is described based on a permineralized stem from the Late Tournaisian (Lower Carboniferous) of the Central Ahnet region, Algeria. It shows similarities with arborescent seed plants described in the Lower Carboniferous of Europe and North America such as Eristophyton waltonii Lacey and Cauloxylon ambiguum Cribbs. However, the primary and secondary vascular system of the stem display an original combination of characters and it is assigned to a new genus: Ahnetia. The preservation of extraxylary tissues (secondary phloem, periderm, cortex) allows formulating hypotheses on the stem's growth potential. The early appearance of a periderm indicates that Ahnetia was capable of significant secondary growth and that the specimen likely represents a young axis of a larger plant. By its Late Tournaisian age, this specimen represents the oldest known occurrence in North Africa of a lignophyte capable of significant secondary growth after the extinction of the progymnosperm Archaeopteris.
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Transitional changes in arborescent lignophytes at the Devonian-Carboniferous boundary
Journal of the Geological Society, 2011Co-Authors: Anne-laure Decombeix, Brigitte Meyer-berthaud, Jean GaltierAbstract:Abstract: It is usually considered that after the extinction of the Devonian tree Archaeopteri s, no new arborescent lignophytes were established before the late Tournaisian. A reassessment of this pattern is presented here based on a three-fold approach: a re-evaluation of the taxic diversity of Tournaisian lignophyte trees based on descriptions of new plants from palaeotropical latitudes, a study of the patterns of phenotypic changes occurring among early lignophytes using a principal coordinate analysis and a phylogenetic analysis of the affinities of the arborescent taxa. The best supported results indicate that a substantial taxonomic and phenotypic diversity of arborescent lignophytes was already established in the first part of the Tournaisian, including some taxa that persisted until the Serpukhovian. Two genera may have originated in the Late Devonian and crossed the Devonian–Carboniferous boundary. Fewer originations and a decrease in phenotypic diversity occurred in the Visean. The phenotypic distinctiveness of tree stems compared with those of other growth forms in the lignophytes is assessed. We propose a scenario in which the presence of lignophyte trees is continuous across the Devonian–Carboniferous boundary, with arborescent taxa distinct from Archaeopteris already present in the latest Devonian, possibly in upland floras, and diversifying significantly soon after the Devonian–Carboniferous boundary. Supplementary material: A list of taxa, characters and matrices used in the principal coordinate analysis and phylogenetic analysis is available at http://www.geolsoc.org.uk/SUP18447.
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Transitional changes in arborescent lignophytes at the Devonian/Carboniferous boundary
Journal of the Geological Society, 2011Co-Authors: Anne-laure Decombeix, Jean Galtier, Brigitte Meyer-berthaudAbstract:It is usually considered that after the extinction of the Devonian tree Archaeopteris, no new arborescent lignophytes were established before the late Tournaisian. A reassessment of this pattern is presented here based on a three-fold approach: a re-evaluation of the taxic diversity of Tournaisian lignophyte trees based on descriptions of new plants from palaeotropical latitudes, a study of the patterns of phenotypic changes occurring among early lignophytes using a principal coordinate analysis and a phylogenetic analysis of the affinities of the arborescent taxa. The best supported results indicate that a substantial taxonomic and phenotypic diversity of arborescent lignophytes was already established in the first part of the Tournaisian, including some taxa that persisted until the Serpukhovian. Two genera may have originated in the Late Devonian and crossed the Devonian-Carboniferous boundary. Fewer originations and a decrease in phenotypic diversity occurred in the Viséan. The phenotypic distinctiveness of tree stems compared with those of other growth forms in the lignophytes is assessed. We propose a scenario in which the presence of lignophyte trees is continuous across the Devonian-Carboniferous boundary, with arborescent taxa distinct from Archaeopteris already present in the latest Devonian, possibly in upland floras, and diversifying significantly soon after the Devonian-Carboniferous boundary.
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Diversity of large woody lignophytes preceding the extinction of Archaeopteris: new data from the middle Tournaisian of Thuringia (Germany)
Review of Palaeobotany and Palynology, 2005Co-Authors: Anne-laure Decombeix, Brigitte Meyer-berthaud, Nick P. Rowe, Jean GaltierAbstract:Anatomically preserved axes representing three lignophyte species occur in the middle Tournaisian deposit of Kahlleite in Thuringia. One is characterized by a small oval eustele, short uniseriate rays, and alternate distichous phyllotaxy. It is assigned to the progymnosperm genus Protopitys. The two others share a eustelic primary vascular system comprising a parenchymatous pith and numerous xylem strands in a peripheral position. The secondary xylem comprises rays that are mostly uniseriate and rarely exceed 20 cells in height. One is referred to as Eristophyton sp.; the second, characterized by ray cells showing a wide range of sizes and shapes is assigned to Aporoxylon primigenium. These records extend the stratigraphical range of Protopitys and Eristophyton down to the middle Tournaisian and confirm their great longevity through most of the Mississippian. They suggest that the diversity of putative arborescent lignophytes co-occurring with Archaeopteris around the D/C boundary but surviving successfully above this limit has been underestimated.
Luc Hance - One of the best experts on this subject based on the ideXlab platform.
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Belgian substages as a basis for an international chronostratigraphic division of the Tournaisian and Viséan
Geological Magazine, 2013Co-Authors: Edouard Poty, Markus Aretz, Luc HanceAbstract:The Tournaisian and Visean were formerly considered as series and in Belgium were divided into two (Hastarian and Ivorian) and three stages (Moliniacian, Livian and Warnantian), which are now considered as substages. The Belgian substages are based on conodonts and foraminifers, and incidentally on rugose corals, and are described here. Their boundaries, biostratigraphy and sequence stratigraphy are well detailed and clearly defined. The base of the Hastarian (lower Tournaisian) corresponds to the base of the Tournaisian (base of Carboniferous); the base of the Ivorian (upper Tournaisian) corresponds to the appearance of the conodont Polygnathus communis carina , a little above the last Siphonodella ; the base of the Moliniacian (lower Visean) corresponds to the base of the Visean stage defined by the first occurrence of the foraminifer Eoparastaffella simplex ; the Livian (middle Visean) corresponds to the foraminiferal MFZ12 Zone and is marked by the appearance of Koskinotextularia and Pojarkovella nibelis ; the base of the Warnantian (upper Visean) is marked by the appearance of Neoarchaediscus , Vissariotaxis , Planospirodiscus , and Palaeotextularia with a bilaminar wall, the index taxa of the MFZ13- Neoarchaediscus Zone. The up-to-date chronostratigraphic subdivision of the Tournaisian and Visean is not limited to Belgium and the surrounding areas. It can be applied through Eurasia as far as South China. The Belgian units could therefore be the basis for a future international division of the Tournaisian into two parts (Hastarian and Ivorian) and of the Visean into three parts (Moliniacian, Livian and Warnantian), corresponding to time intervals of c. 5–8 Ma.
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upper devonian and mississippian foraminiferal and rugose coral zonations of belgium and northern france a tool for eurasian correlations
Geological Magazine, 2006Co-Authors: Edouard Poty, Francois Xavier Devuyst, Luc HanceAbstract:The radiation of early Carboniferous foraminifers and rugose corals following the Devonian–Carboniferous crisis offers the best tool for high-resolution correlations in the Mississippian, together with the conodonts in the Tournaisian, notably in the Namur–Dinant Basin. However, some of the guides are facies-controlled and an integrated approach combining biostratigraphy, sedimentology and sequence stratigraphy is critical to identify delayed entries, potential stratigraphic gaps and to avoid diachronous correlations. The main difficulty is in correlating shallow and deeper water facies at any given time. In existing zonations, the Visean part of the scheme is always more detailed, reflecting the widespread development of shallow-water platforms in the early Visean which created conditions more suitable for foraminifers and rugose corals over large areas. In contrast, the Tournaisian zones, less well documented, reflect unfavourable environmental conditions in the lower ramp (Dinant Sedimentation Area) and pervasive dolomitization of the inner ramp (Condroz and Namur Sedimentation Areas). Recent progress in understanding the Belgian early Carboniferous sequence stratigraphy and lithostratigraphy, and revision of the biostratigraphy of the key sections, strongly modify former biostratigraphic interpretations. Improvements mainly concern the latest Devonian, the late Tournaisian and the early Visean. The late Devonian and the Tournaisian are equated with foraminifer zones DFZ1 to DFZ8 and MFZ1 to MFZ8 respectively. The Visean correlates with zones MFZ9 to MFZ14. Zone MFZ15 straddles the Visean–Namurian boundary and Zone MFZ16 is the youngest Mississippian zone. The rugose corals allow the recognition of ten zones, RC0 to RC9, covering the Strunian (late Famennian) to Serpukhovian interval. Discrepancies with former zonations are discussed. The Moliniacian Stage is emended to restore the coincidence between its base and that of the Visean.
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Sequence stratigraphical study of the Tournaisian strata in Belgium and Southern China
Geologica Belgica, 2001Co-Authors: An Smeesters, Philippe Muchez, Luc HanceAbstract:Strata of late Devonian and Tournaisian age in Belgium and Southern China were studied sedimentologically. This detailed study integrated into a biostratigraphical framework, based on foraminiferal zonation, allowed the construction of a sequence stratigraphical model for both areas. Based on these models a correlation on the scale of third order sequences between these two widely separated depositional environments can be made. This indicates the eustatic nature of the sea-level changes that caused the sedimentological changes during the Tournaisian.
