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Paulian Dumitrica - One of the best experts on this subject based on the ideXlab platform.
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Taxonomy of Paleozoic Radiolarian genera
2017Co-Authors: Paula Noble, Martial Caridroit, Paulian Dumitrica, Noritoshi Suzuki, Taniel Danelian, Jonathan Aitchison, Jörg Maletz, Jessie Cuvelier, Luis O'doghertyAbstract:This chapter is to be used as companion text with the companion chapter, an illustrated catalogue of Paleozoic Radiolarian genera found in this volume, and serves the purpose of giving the reader explanation for any taxonomic operations undertaken during the course of constructing the catalogue. These operations refer to the status of the genera as valid, junior synonym, homonym, nomen nudum, nomen dubium, or not Radiolaria. We also include diagnoses and/or descriptions in the original language published, English translations where needed, and locality and age information for the type material.
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comment on the species and age determination published by li et al discovery of radiolaria from upper cretaceous oceanic red beds in daba kangmar and its paleogeographic implication palaeogeography palaeoclimatology palaeoecology 312 2011 127 137
2015Co-Authors: Luis Odogherty, Paulian Dumitrica, Spela Gorican, Jonathan C AitchisonAbstract:Abstract Li et al. (2011a, Discovery of Radiolaria from Upper Cretaceous Oceanic Red Beds in Daba, Kangmar and its paleogeographic implication. Palaeogeography, Palaeoclimatology, Palaeoecology 312, 127–137) reported three Radiolarian assemblages from Cretaceous Oceanic Red Beds (CORBs) in Chuangde Formation, which they assigned to the Late Cretaceous. With only very few exceptions all species have been erroneously determined and, consequently, the age of the samples was wrongly interpreted. None of these Radiolarians suggest a Late Cretaceous age, late Santonian to early Maastrichtian, as proposed in the publication. On the contrary, all Radiolarians are indicators of an Early Cretaceous age, early Barremian to earliest Albian.
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taxonomic study of spongy spumellarian radiolaria with three and four coplanar spines or arms from the middle carnian late triassic of the koseyahya nappe elbistan se turkey and other triassic localities
2013Co-Authors: Paulian Dumitrica, Ugur Kagan Tekin, Yavuz BediAbstract:The present article is a taxonomic study of all spongy spumellarian Radiolarian taxa with three and four coplanar spines or spongy arms occurring in the middle Carnian from the Koseyahya section, near the town of Elbistan, SE Turkey. This fauna is characteristic of the Tetraporobrachia haeckeli Radiolarian Zone, and comes from an 8 m thick succession of clayey-cherty limestones occurring at the lower part of the section. In addition, a few species from the Middle and Upper Triassic from other areas have been also included in this study to improve some generic diagnoses, and to better comprehend the diversity and evolutionary trends of some genera, subfamilies and families. The taxonomy at the generic and suprageneric levels is based primarily on the types of microsphere. This new approach allowed new taxonomic arrangements of genera and suprageneric units, and suggested new phylogenetic relationships among these Radiolarians and between them and younger Radiolarians. The authors discuss and describe 69 species, of which 37 are new, and 14 genera, of which three are new (Paraparonaella, Pseudangulobracchia, and Ropanaella). The genus Triassoastrum and others are reinterpreted. All genera studied are assigned to five subfamilies, of which two are new (Tetrapaurinellinae and Triassocrucellinae), and two families (Tritrabidae and Veghicycliidae). Nine species in open nomenclature are also illustrated.
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taxonomic study of the tetrahedral pentagonal and hexagonal spongy spumellarian radiolaria from the middle carnian late triassic of the koseyahya nappe elbistan se turkey and other triassic localities
2013Co-Authors: Paulian Dumitrica, Ugur Kagan Tekin, Yavuz BediAbstract:This article is a taxonomic study of all spongy Radiolarian taxa with five to six coplanar and four tetrahedrally disposed spines or spongy arms occurring in the middle Carnian from the Koseyahya section, near the town of Elbistan, SE Turkey. This fauna is characteristic of the Tetraporobrachia haeckeli Radiolarian Zone, and comes from an 8 m thick succession of clayey–cherty limestones occurring at the lower part of the section. In addition, a few species from the Middle and Upper Triassic from other areas have been also included in this study to improve some generic diagnoses and to better understand the diversity and evolutionary trends of some genera, subfamilies and families. The taxonomy at the generic and suprageneric levels is based primarily on the types of microsphere. This new approach allowed new taxonomic arrangements of genera and suprageneric units, and suggested new and unexpected phylogenetic relationships among these Radiolarians and between them and younger Radiolarians. The authors discuss and describe 42 species, of which 36 are new, and 12 genera of which three are new (Charlottalum, Pentaspongodisculus, and Trimiducaella). The genera Pseudohagiastrum Pessagno, Natraglia Pessagno, Cantalum Pessagno and others are reinterpreted. All the genera studied, except Charlottalum, are assigned to three subfamilies, of which two (Pseudohagiastrinae and Trimiducinae) are new, and to two families (Angulobracchiidae and Relindellidae). The genus Charlottalum is described to replace the genus Cantalum, which has been erroneously used until present for Late Triassic pantanelliids with four tetrahedrally disposed three-bladed spines.
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triassic Radiolarian biostratigraphy
2010Co-Authors: Luis Odogherty, Spela Gorican, Elizabeth S Carter, Paulian DumitricaAbstract:This paper summarizes 30 years of research on the biostratigraphy of Triassic radio- larians and presents a correlation of currently-used Radiolarian zonations established in North America, Europe, Japan and Far East Russia. An up-to-date stratigraphic distribution of all hitherto described and still valid Triassic genera is provided. This new range chart consists of 282 genera and allows an accurate dating to substage level. It also clearly manifests general trends in radiolar- ian evolution through the Triassic. The end-Permian extinction, the most severe extinction in the history of Radiolarians, was followed by a long recovery until the early Anisian. The middle and late Anisian were then characterized by a rapid explosion of new morphologies. Maximum generic diversity was attained during the early Carnian, but the first severe extinctions also occurred in the Carnian. A progressive decline of diversity took place through the Norian and Rhaetian, and ended in a mass extinction around the Triassic- Jurassic boundary. Since the revolution that signified the use of the hydrofluoric acid method in extracting Radiolarians from hard siliceous rocks, Radiolarians have proven to be of great importance in reconstructing the stratigraphy of the Mesozoic, particularly the Triassic System. This methodology, discovered independently by Dumitrica (1970) and Pessagno & Newport (1972), together with the building of a new taxonomic system for Mesozoic Radiolarians,
Jonathan C Aitchison - One of the best experts on this subject based on the ideXlab platform.
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adding a new dimension to investigations of early Radiolarian evolution
2019Co-Authors: Sarah Kachovich, Jiani Sheng, Jonathan C AitchisonAbstract:Knowledge of the detailed architecture of the earliest Radiolarian microfossils is key to resolving the evolution and systematics of this important group of marine protozoans. Non-destructive methods for observing the complexity within the internal structures of their siliceous skeletons have long eluded paleontologists. By developing methodologies that overcome some limitations of existing micro-computed tomography (micro-CT) we demonstrate a technique with potential to provide new insight into their evolution. Using 3D micro-CT data to generate models for six well-preserved siliceous Radiolarian skeletons from the Middle Cambrian Inca Formation in far north Queensland, Australia and the Middle Ordovician Piccadilly Formation, in western Newfoundland, Canada, we can reconstruct phylogenetic relationships amongst some of the earliest Radiolarians. Better knowledge of early Radiolarian morphologies clarifies the vital function of internal structures and hierarchical diagnosis across a range of taxonomic affiliations.
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inventory of paleozoic Radiolarian species 1880 2016
2017Co-Authors: Jonathan C Aitchison, Noritoshi Suzuki, Luis OdoghertyAbstract:This paper presents, for the first time, a complete list of Paleozoic Radiolarian species (mainly Polycystina) described between 1880 and early 2016. It records 2323 names of taxa described originally as new species or subspecies that have been assigned to Radiolarians. This list attempts to only provide an objective record without revision of taxonomic status, and thus includes invalid taxa, junior objective or subjective synonyms, nomina dubia and nomina nuda.
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comment on the species and age determination published by li et al discovery of radiolaria from upper cretaceous oceanic red beds in daba kangmar and its paleogeographic implication palaeogeography palaeoclimatology palaeoecology 312 2011 127 137
2015Co-Authors: Luis Odogherty, Paulian Dumitrica, Spela Gorican, Jonathan C AitchisonAbstract:Abstract Li et al. (2011a, Discovery of Radiolaria from Upper Cretaceous Oceanic Red Beds in Daba, Kangmar and its paleogeographic implication. Palaeogeography, Palaeoclimatology, Palaeoecology 312, 127–137) reported three Radiolarian assemblages from Cretaceous Oceanic Red Beds (CORBs) in Chuangde Formation, which they assigned to the Late Cretaceous. With only very few exceptions all species have been erroneously determined and, consequently, the age of the samples was wrongly interpreted. None of these Radiolarians suggest a Late Cretaceous age, late Santonian to early Maastrichtian, as proposed in the publication. On the contrary, all Radiolarians are indicators of an Early Cretaceous age, early Barremian to earliest Albian.
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lower and middle devonian Radiolarian biozonation of the gamilaroi terrane new england orogen eastern australia
1999Co-Authors: Jonathan C Aitchison, A M Davis, James M C Stratford, Frances C P SpillerAbstract:Seven distinctive Radiolarian assemblages defined from the Gamilaroi terrane of eastern Australia form the basis of an uppermost Lower to Middle Devonian Radiolarian biostratigraphy. In ascending order these are the: Stigmosphaerostylus horrida, Helenifore laticlavium, Circulaforma admissarius, Helenifore pilosidiscus n. sp., Protoholoeciscus hindea, Ceratoikiscum regalinodus, and Trilonche minax assemblages. Gamilaroi terrane sedimentation occurred during the interval Early (Pragian) to Late (Frasnian) Devonian in a volcanic island arc environment in which Radiolarians were abundant but sedimentary facies were locally variable. Radiolarian assemblages can be used for terrane-wide correlation. Although assemblages are dominated by spumellarians they also include more distinctive ceratoikiscid forms. Two new ceratoikiscid taxa: Circulaforma davidi n. sp. and Helenifore pilosidiscus n. sp are described.
Li Guobiao - One of the best experts on this subject based on the ideXlab platform.
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Evolution of mid-Cretaceous Radiolarians in response to oceanic anoxic events in the eastern Tethys (southern Tibet, China)
2019Co-Authors: Wang Tianyang, Li Guobiao, Aitchison, Jonathan C., Ding Lin, Sheng JianiAbstract:Oceanic anoxic events (OAEs) are well-known from their widespread black shale and carbon isotopic excursions in the (western and eastern) Tethys and Atlantic Ocean. However, the weakest link in the studies of the OAEs is biological evolution. Sedimentological, biostratigraphical and geochemical data from Albian to Coniacian strata in southern Tibet recorded turnover events and fluctuations in diversity of the Radiolarian fauna within the eastern Tethys during OAE 1d and OAE 2. Abundant Radiolarian fossils were obtained from the Gyabula Formation, with 93 species from 43 genera identified and assigned to the mid to Upper Cretaceous Acaeniotyle umbilicata, Archaeospongoprunum tehamaensis, Crucella cachensis, Alievium superbum, and Dictyomitra formosa zones. The association of carbon isotopic excursions, black shale and Radiolarian turnover indicates extensive changes in the ocean-climate system. Nutrients are made increasing available to the marine plankton through submarine volcanic activity and rising sea-level, which were a likely cause of Radiolarian turnover at/or near the OAEs. Active submarine tectonism-volcanism leads to the expansion of the hypoxic zone and may cause many deeper dwelling forms to become extinct whereas most of the shallower dwelling Radiolarians survive. Radiolarian evolution thus provides a useful record with which to seek understand relationships between climate, paleoceanographic processes and plankton evolution
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discovery of radiolaria from upper cretaceous oceanic red beds in daba kangmar and its paleogeographic implication
2011Co-Authors: Li Guobiao, Jansa Luba, Wan Xiaoqiao, Pan Mao, Xie DanAbstract:article A group of varicolored marine deposits, including red colored beds, are widespread in the Kangmar area, southern Tibet. They are lithologically similar to the Upper Cretaceous Oceanic Red Beds (CORBs) (the Chuangde Formation) outcropping at other localities in southern Tibet. At Daba locality, they are mainly com- posed of intercalated pelagic red clays and reddish colored pelagic limestones. Micropaleontologic study of the strata led to the discovery of Radiolarians in siliceous rocks and siliceous limestones. Radiolaria preserva- tion is mostly satisfactory and fifty-four species from forty-nine genera were identified. These allow recogni- tion of three main Radiolarian assemblages: Cavaspongia califoniaensis — Xitus spicularius assemblage, Praeconocaryomma lipmanae — Clathropyrgus titthium assemblage, and Lithostrobus punctulatus — Lithocampe marinae assemblage. Occurrence of these Radiolarian assemblages indicate a Campanian age of the CORBs at Daba, corroborated by co-occurring planktic foraminifers. Radiolarian and foraminiferal microfossil evidence and lithology of the strata indicate that the sediments were deposited at the lower continental margin of the Indian continental
Luis Odogherty - One of the best experts on this subject based on the ideXlab platform.
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Radiolarian phylogeny around the jurassic cretaceous boundary and Radiolarian occurrences in the bosso valley section central italy
2018Co-Authors: Atsushi Matsuoka, Luis Odogherty, Spela Gorican, Peter Baumgartner, Marco Chiari, Angela BertinelliAbstract:The Global Boundary Stratotype Section and Point (GSSP) of the Jurassic–Cretaceous boundary (JKB) is the last among the GSSPs in the Phanerozoic. It is defined as the base of the Berriasian Stage. The formal definition was decided in 2016 to use the base of the Calpionella alpin a Subzone as the primary marker by the Berriasian Working Group in the International Subcommission on Cretaceous Stratigraphy. The definition is satisfactorily applicable for shallow marine deposits within the western Tethys, north Atlantic and central-south America. Unfortunately, the primary marker taxon cannot be found in the Pacific and circum-Pacific regions since the distribution of Calpionellids is limited to the western Tethys, north Atlantic and central-south America. To determine the base of the Berriasian outside of these regions, alternative markers are needed. Radiolarians are good candidates for defining the JKB because they are wide spread and can be found both shallow and deep sedimentary facies. Pelagic sequences across the JKB have been reported in ODP/IODP sites in the western Pacific and land sections in Japan, the Philippines, southern Tibet, Iran and others. Evolutionary lineages of several Radiolarian taxa across the JKB are reviewed and suitable bioevents, which are approximate to the JKB, are presented. These lineages include the Radiolarian genera: Alievium, Archaeodictyomitra, Cinguloturris, Complexapora, Crococapsa, Doliocapsa, Emiluvia, Eucyrtidiellum, Hemicryptocapsa, Hsuum, Loopus, Mirifusus, Mesovallupus, Neorelumbra, Pantanellium, Protovall u pus, Protunuma, Pseudodictyomitra, Ristola, Spinosicapsa , Tethysetta, Thanarla ， Vallupus ， Xitus , Zhamoidellum . Among them the Loopus – Pseudodictyomitra lineage and the Protovallupus – Mesovallupus – Vallupus lineage can be the most important phylogeny for defining the JKB. As discussed by Gorican et al. (2018), the evolutionary first appearance datums (FADs) within firmly recognized lineages are extremely valuable. The Loopus – Pseudodictyomitra lineage is more advantageous than the Protovallupus – Mesovallupus – Vallupus lineage because the former has a much wider paleobiogeographic distribution than the latter. Applying to the so far established Radiolarian zones, the JKB lies within the Unitary Association Zone 13 of Baumgartner et al. (1995) and within the Pseudodictyomitra carpatica Zone of Matsuoka (1995). The base of the Pseudodictyomitra carpatica Zone is defined by the evolutionary FAD of Pseudodictyomitra carpatica . Detailed morphological analysis of Loopus and Pseudodictyomitra species is presented and the relationship between the JKB and speciation within the lineage is discussed. The Bosso Valley section in Umbria–Marche, central Italy, is one of potential candidates for GSSP of the JKB. The Maiolica Formation, which crosses the JKB, is characterized by whitish, beige to gray colored, well-bedded micritic limestones with abundant black to gray chert layers and nodules. Calpionellid stratigraphy and magnetostratigraphy have been studied sufficiently in the section (Housa et al. , 2004). The base of the Calpionella alpina Subzone, i.e. , the JKB, is placed between Beds 77 and 78 (Housa et al. , 2004). We carried out detailed field observations and careful sample collections in a 4-m interval across the JKB. Acid-etched examination of rock samples revealed that well-preserved Radiolarians are recognized inside the lime part near the chert layers or nodules. Three samples of micritic limestone below the JKB and two samples above the JKB yield moderatly-preserved Radiolarians. The result of Radiolarian faunal analysis in the Bosso Valley section is presented.
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inventory of paleozoic Radiolarian species 1880 2016
2017Co-Authors: Jonathan C Aitchison, Noritoshi Suzuki, Luis OdoghertyAbstract:This paper presents, for the first time, a complete list of Paleozoic Radiolarian species (mainly Polycystina) described between 1880 and early 2016. It records 2323 names of taxa described originally as new species or subspecies that have been assigned to Radiolarians. This list attempts to only provide an objective record without revision of taxonomic status, and thus includes invalid taxa, junior objective or subjective synonyms, nomina dubia and nomina nuda.
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comment on the species and age determination published by li et al discovery of radiolaria from upper cretaceous oceanic red beds in daba kangmar and its paleogeographic implication palaeogeography palaeoclimatology palaeoecology 312 2011 127 137
2015Co-Authors: Luis Odogherty, Paulian Dumitrica, Spela Gorican, Jonathan C AitchisonAbstract:Abstract Li et al. (2011a, Discovery of Radiolaria from Upper Cretaceous Oceanic Red Beds in Daba, Kangmar and its paleogeographic implication. Palaeogeography, Palaeoclimatology, Palaeoecology 312, 127–137) reported three Radiolarian assemblages from Cretaceous Oceanic Red Beds (CORBs) in Chuangde Formation, which they assigned to the Late Cretaceous. With only very few exceptions all species have been erroneously determined and, consequently, the age of the samples was wrongly interpreted. None of these Radiolarians suggest a Late Cretaceous age, late Santonian to early Maastrichtian, as proposed in the publication. On the contrary, all Radiolarians are indicators of an Early Cretaceous age, early Barremian to earliest Albian.
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triassic Radiolarian biostratigraphy
2010Co-Authors: Luis Odogherty, Spela Gorican, Elizabeth S Carter, Paulian DumitricaAbstract:This paper summarizes 30 years of research on the biostratigraphy of Triassic radio- larians and presents a correlation of currently-used Radiolarian zonations established in North America, Europe, Japan and Far East Russia. An up-to-date stratigraphic distribution of all hitherto described and still valid Triassic genera is provided. This new range chart consists of 282 genera and allows an accurate dating to substage level. It also clearly manifests general trends in radiolar- ian evolution through the Triassic. The end-Permian extinction, the most severe extinction in the history of Radiolarians, was followed by a long recovery until the early Anisian. The middle and late Anisian were then characterized by a rapid explosion of new morphologies. Maximum generic diversity was attained during the early Carnian, but the first severe extinctions also occurred in the Carnian. A progressive decline of diversity took place through the Norian and Rhaetian, and ended in a mass extinction around the Triassic- Jurassic boundary. Since the revolution that signified the use of the hydrofluoric acid method in extracting Radiolarians from hard siliceous rocks, Radiolarians have proven to be of great importance in reconstructing the stratigraphy of the Mesozoic, particularly the Triassic System. This methodology, discovered independently by Dumitrica (1970) and Pessagno & Newport (1972), together with the building of a new taxonomic system for Mesozoic Radiolarians,
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an illustrated and revised catalogue of mesozoic Radiolarian genera objectives concepts and guide for users
2009Co-Authors: Luis Odogherty, Paulian Dumitrica, Elizabeth S Carter, Spela Goriccan, Patrick De WeverAbstract:ABSTRACT This revision paper represents the final report by the InterRad Mesozoic Working Group on the taxonomy and stratigraphy of Mesozoic Radiolarians at generic level. The review reports 915 genera and encompasses the type species' illustration of all described nominal genera of Mesozoic Radiolarians (superorder Polycystina) from 1867, when the first Mesozoic Radiolarian was described, to 2008. This work is organized as an image catalogue of genera, where each type species is re-illustrated with a graphic scale bar indicating its magnification. Associated with each image is the most basic information that allows the reader quick location of the original publication where both genus and type species were described and/or illustrated. The review undergone here confirms the taxonomic validity of all genera according to the ICZN rules. Order and family assignment, synonymies and stratigraphic ranges are also fully analyzed. The review is divided in two parts: the Triassic and the Jurassic-Cretaceous. This...
Spela Gorican - One of the best experts on this subject based on the ideXlab platform.
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Radiolarian phylogeny around the jurassic cretaceous boundary and Radiolarian occurrences in the bosso valley section central italy
2018Co-Authors: Atsushi Matsuoka, Luis Odogherty, Spela Gorican, Peter Baumgartner, Marco Chiari, Angela BertinelliAbstract:The Global Boundary Stratotype Section and Point (GSSP) of the Jurassic–Cretaceous boundary (JKB) is the last among the GSSPs in the Phanerozoic. It is defined as the base of the Berriasian Stage. The formal definition was decided in 2016 to use the base of the Calpionella alpin a Subzone as the primary marker by the Berriasian Working Group in the International Subcommission on Cretaceous Stratigraphy. The definition is satisfactorily applicable for shallow marine deposits within the western Tethys, north Atlantic and central-south America. Unfortunately, the primary marker taxon cannot be found in the Pacific and circum-Pacific regions since the distribution of Calpionellids is limited to the western Tethys, north Atlantic and central-south America. To determine the base of the Berriasian outside of these regions, alternative markers are needed. Radiolarians are good candidates for defining the JKB because they are wide spread and can be found both shallow and deep sedimentary facies. Pelagic sequences across the JKB have been reported in ODP/IODP sites in the western Pacific and land sections in Japan, the Philippines, southern Tibet, Iran and others. Evolutionary lineages of several Radiolarian taxa across the JKB are reviewed and suitable bioevents, which are approximate to the JKB, are presented. These lineages include the Radiolarian genera: Alievium, Archaeodictyomitra, Cinguloturris, Complexapora, Crococapsa, Doliocapsa, Emiluvia, Eucyrtidiellum, Hemicryptocapsa, Hsuum, Loopus, Mirifusus, Mesovallupus, Neorelumbra, Pantanellium, Protovall u pus, Protunuma, Pseudodictyomitra, Ristola, Spinosicapsa , Tethysetta, Thanarla ， Vallupus ， Xitus , Zhamoidellum . Among them the Loopus – Pseudodictyomitra lineage and the Protovallupus – Mesovallupus – Vallupus lineage can be the most important phylogeny for defining the JKB. As discussed by Gorican et al. (2018), the evolutionary first appearance datums (FADs) within firmly recognized lineages are extremely valuable. The Loopus – Pseudodictyomitra lineage is more advantageous than the Protovallupus – Mesovallupus – Vallupus lineage because the former has a much wider paleobiogeographic distribution than the latter. Applying to the so far established Radiolarian zones, the JKB lies within the Unitary Association Zone 13 of Baumgartner et al. (1995) and within the Pseudodictyomitra carpatica Zone of Matsuoka (1995). The base of the Pseudodictyomitra carpatica Zone is defined by the evolutionary FAD of Pseudodictyomitra carpatica . Detailed morphological analysis of Loopus and Pseudodictyomitra species is presented and the relationship between the JKB and speciation within the lineage is discussed. The Bosso Valley section in Umbria–Marche, central Italy, is one of potential candidates for GSSP of the JKB. The Maiolica Formation, which crosses the JKB, is characterized by whitish, beige to gray colored, well-bedded micritic limestones with abundant black to gray chert layers and nodules. Calpionellid stratigraphy and magnetostratigraphy have been studied sufficiently in the section (Housa et al. , 2004). The base of the Calpionella alpina Subzone, i.e. , the JKB, is placed between Beds 77 and 78 (Housa et al. , 2004). We carried out detailed field observations and careful sample collections in a 4-m interval across the JKB. Acid-etched examination of rock samples revealed that well-preserved Radiolarians are recognized inside the lime part near the chert layers or nodules. Three samples of micritic limestone below the JKB and two samples above the JKB yield moderatly-preserved Radiolarians. The result of Radiolarian faunal analysis in the Bosso Valley section is presented.
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comment on the species and age determination published by li et al discovery of radiolaria from upper cretaceous oceanic red beds in daba kangmar and its paleogeographic implication palaeogeography palaeoclimatology palaeoecology 312 2011 127 137
2015Co-Authors: Luis Odogherty, Paulian Dumitrica, Spela Gorican, Jonathan C AitchisonAbstract:Abstract Li et al. (2011a, Discovery of Radiolaria from Upper Cretaceous Oceanic Red Beds in Daba, Kangmar and its paleogeographic implication. Palaeogeography, Palaeoclimatology, Palaeoecology 312, 127–137) reported three Radiolarian assemblages from Cretaceous Oceanic Red Beds (CORBs) in Chuangde Formation, which they assigned to the Late Cretaceous. With only very few exceptions all species have been erroneously determined and, consequently, the age of the samples was wrongly interpreted. None of these Radiolarians suggest a Late Cretaceous age, late Santonian to early Maastrichtian, as proposed in the publication. On the contrary, all Radiolarians are indicators of an Early Cretaceous age, early Barremian to earliest Albian.
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triassic Radiolarian biostratigraphy
2010Co-Authors: Luis Odogherty, Spela Gorican, Elizabeth S Carter, Paulian DumitricaAbstract:This paper summarizes 30 years of research on the biostratigraphy of Triassic radio- larians and presents a correlation of currently-used Radiolarian zonations established in North America, Europe, Japan and Far East Russia. An up-to-date stratigraphic distribution of all hitherto described and still valid Triassic genera is provided. This new range chart consists of 282 genera and allows an accurate dating to substage level. It also clearly manifests general trends in radiolar- ian evolution through the Triassic. The end-Permian extinction, the most severe extinction in the history of Radiolarians, was followed by a long recovery until the early Anisian. The middle and late Anisian were then characterized by a rapid explosion of new morphologies. Maximum generic diversity was attained during the early Carnian, but the first severe extinctions also occurred in the Carnian. A progressive decline of diversity took place through the Norian and Rhaetian, and ended in a mass extinction around the Triassic- Jurassic boundary. Since the revolution that signified the use of the hydrofluoric acid method in extracting Radiolarians from hard siliceous rocks, Radiolarians have proven to be of great importance in reconstructing the stratigraphy of the Mesozoic, particularly the Triassic System. This methodology, discovered independently by Dumitrica (1970) and Pessagno & Newport (1972), together with the building of a new taxonomic system for Mesozoic Radiolarians,
