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The Silurian palaeontology and stratigraphy of the Qinghai-Tibetan Plateau have been studied for more than 100 years. With the launch of the Second Tibetan Plateau Scientific Expedition and Research, it is necessary to update the summaries of the Silurian stratigraphy and fossil assemblages of the Qinghai-Tibetan Plateau and their correlation with its surrounding areas. In this study, we have selected 33 sections from the Qinghai-Tibetan Plateau and its surroundings areas, summarised the available data in terms of stratigraphic regionalisation, lithostratigraphy, chronostratigraphy, and biostratigraphy, and divided the study area into four stratigraphic provinces: the Xizang-Western Yunnan-Western Sichuan Province, the Kunlun-Qilian Province, the South China Province, and the Tarim Province. In general, the Silurian strata in the Qinghai-Tibetan Plateau is more complete than those in other areas of China. Palaeobiogeographical studies of the vertebrate faunas, sporomorph assemblages, and brachiopod faunas of the study area indicate a closer geographical relationship between the South China, Tarim, and Indochina palaeoplates, than previously considered. Compared with the surrounding areas where Silurian strata have been extensively studied, the study of Silurian strata in the main part of the Qinghai-Tibetan Plateau is still in the preliminary stage. In the future, it is necessary to conduct research on the age, distribution, and resource potential of basal Silurian black shales to provide new directions for shale gas exploration and development in China. The shallow marine strata of the middle to upper Silurian require further subdivision. Considering that the Silurian System in the Qinghai-Tibetan Plateau is more complete, it has the potential to supplement and improve the study of the carbon isotope stratigraphy of the Silurian in China. [ABSTRACT FROM AUTHOR]

The new hexactinellid stiodermatid Turgidaspongia porosa gen. et sp. nov. is described from the Ordovician-Silurian boundary sequence in Beigong of Jingxian County, south Anhui Province, China. The spherical, thin-walled species possessed unique features including unusually large parietal gaps on the body wall, swollen hexactines as hypodermalia, and two different sizes of stauractines as dermalia and parenchymalia respectively. Based on the new material, the family Stiodermatidae is revised here, including five genera after reassessment, i.e., Rigbyella, Thoracospongia, Stioderma, Uralonema, and Turgidaspongia porosa gen. et sp. nov. The new species is well preserved with typical enlarged hypodermal hexactines with swollen rays and large, subcircular parietal gaps, giving an illuminating insight into the affinity between the new species and other taxa in Stiodermatidae. It also provides a link between the Cambrian stiodermatid lineage and late Palaeozoic stiodermatid lineage. The uneven distribution of the swollen dermalia in the new species may relate to the sloughing of the dermal spicules causing by the nutrient deficiency. The unique rigid skeleton structure and unusually large parietal gaps probably represent new attempts on the skeletal evolution of hexactinellids in the Palaeozoic. [ABSTRACT FROM AUTHOR]

Seventeen trilobite species belonging to 16 genera and 13 families are systematically documented from the Houping Formation (upper Dapingian-lower Darriwilian, Middle Ordovician) at the Datangkou and Dacao sections, Chengkou, northern Chongqing. Of these, a new species, Mioptychopyge chengkouensis sp. nov., is established and described. New morphological information is provided for previously known species on the basis of new specimens. Two trilobite associations based on faunal composition and dominant forms are distinguished from the Houping Formation, in ascending order, the Agerina Association (from the lower and middle members) and the Nileus-Illaenus Association (from the upper member). The Agerina Association lived in an inner shelf margin environment with carbonate substrate above storm wave base (<70 m deep), whereas the Nileus-Illaenus Association developed in a shallow outer shelf environment below storm wave base (>70 m deep), indicating a rise of relative sea level corresponding to the early Darriwilian transgression. The cluster and nonmetric multidimensional scaling analyses of the trilobites in the formation show that the fauna had a strong endemicity to South China and a close biogeographic connection with east Peri-Gondwana, especially Tarim, Annamia and central Iran. [ABSTRACT FROM AUTHOR]

Late Llandovery and Wenlock conodonts are still inadequately documented in China, with data collected chiefly from the Baizitian section in Yanbian County, Sichuan Province, south‐west China. A collection of over 32 000 conodont elements was recovered from 38 samples from the Xiabaizitian and Shangbaizitian formations at this classic locality. The conodont fauna is dominated by cosmopolitan species and can be assigned to 50 species representing 17 genera. Of these, one new species, Apsidognathus yanbianensis sp. nov., is proposed herein. Six conodont zones are recognized in this section, including the Pterospathodus eopennatus Zone, the Pt. amorphognathoides angulatus Taxon‐range Zone of the Pt. a. amorphognathoides Superzone, the Kockelella ranuliformis Zone, the Kockelella walliseri Taxon‐range Zone, and the Kockelella patula Taxon‐range Zone, in ascending order. These zones can be correlated with other conodont zones around the world based on the occurrences of the stratigraphically diagnostic species. Moreover, the stratigraphical ranges of Pterospathodus enable greater understanding of the correlation of the Telychian guide taxa. The conodont biodiversity changes and faunal turnover across the Silurian Ireviken Bioevent are here documented for the first time in the Baizitian section from the South China palaeoplate. [ABSTRACT FROM AUTHOR]

Middle to Late Ordovician carbonates were collected in South China (Anhui Province) from the Kuniutan, Datianba, and Pagoda formations in the Dingxiang and Daling sections and analysed for high‐resolution carbon isotope chemostratigraphy. An increase by 0.4‰ in δ13Ccarb is observed in the upper part of the Kuniutan Formation (Eoplacognathus pseudoplanus Biozone), representing the rising limb of the Middle Darriwilian Isotopic Carbon Excursion (MDICE). In the upper part of the Datianba Formation, positive shifts of ca. 1‰ are recorded in the studied section which compare with the carbon shifts reported in North America and Baltoscandia. A pronounced positive δ13Ccarb excursion of ca. 1.5‰ from the lower part of the Pagoda Formation can be correlated with the global Guttenberg Isotopic Carbon Excursion (GICE). The documentation of three carbon isotope shifts in this study provides new evidence for changes in the global carbon cycle from Darriwilian to Early Katian which could have been influenced by changes in global climate and primary productivity. [ABSTRACT FROM AUTHOR]

New conodont and stable isotope data are presented from the classical Baizitian section in the Yanbian County of Sichuan Province, South China. The Telychian to Sheinwoodian strata were sampled and studied for carbon isotope stratigraphy and conodont biostratigraphy. The paired δ13C carb and δ13C org data reveal a pronounced positive excursion, the Manitowoc carbon isotope excursion (Manitowoc CIE, 'Manitowoc Excursion') spanning the upper Pterospathodus eopennatus Zone and the lower Pterospathodus amorphognathoides amorphognathoides Superzone, with an increase of ca. 2‰ in δ13C carb and ca. 5‰ in δ13C org. Well-bracketed by conodont biostratigraphy, the Manitowoc CIE is an essential tie-point for correlation between the Baizitian succession and the Telychian strata of Baltica and Laurentia. Our new δ13C carb and δ13C org data imply that the carbon isotope excursion previously recognized as the 'Ireviken Excursion' (Early Sheinwoodian Carbon Isotope Excursion) at Baizitian should be revised as being the Manitowoc CIE. The Δ13C data presented in this study further suggest a slight concurrent drop of atmospheric CO 2 , and thus add evidence for a perturbation of the global carbon cycle during the middle Telychian. Based on the combined information from the conodont apatite oxygen isotope records from Estonia and the significant stratigraphic gaps recognized at the Baizitian section, we propose that the latter stratigraphic gaps should correlate with the Telychian Valgu and the early Sheinwoodian glaciation. • A first paired early Silurian δ13C carb and δ13C org record from South China. • Integrated conodont and chemostratigraphy shows stratigraphic gaps in South China related to Telychian and Sheinwoodian glacials. • The stratigraphic value of the Telychian Manitowoc Carbon Isotope Excursion for global correlations. • elationship between the δ18O record and early Silurian climate change and glacioeustasy. • Early Silurian as a time of drastic climate changes includes various cooling events and Gondwana glaciations such as the Valgu Glaciation, the Late Telychian Glaciation during the Manitowoc Icehouse, and the Sheinwoodian Glaciation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Silurian (Telychian) conodont distribution on the Yangtze Platform of South China is quantitatively studied for the first time. • Water-depth controlled Dapsilodus-Decoriconus Biofacies and Apsidognathus-Galerodus Biofacies are recognised on the Yangtze Platform. • Distribution of these biofacies can be closely related to Early Silurian sea-level changes. Diverse Telychian (Llandovery Series, Silurian System) conodont faunas have been documented from the South China Palaeoplate. Based on data from six selected sections in the Yangtze Platform, the spatial distribution of the Telychian conodont associations is investigated in detail by use of multivariate statistical methods. Two conodont biofacies are recognised within the Pterospathodus eopennatus Biozone: Dapsilodus-Decoriconus Biofacies and Apsidognathus-Galerodus Biofacies. The former is interpreted as representing a relatively deeper-water environment. The Apsidognathus-Galerodus Biofacies is widely distributed on the Yangtze Platform and is indicative of a shallower depositional setting. Vertical changes of conodont biofacies in the Baizitian and Xuanhe sections permit the recognition of transgressive–regressive patterns which are closely similar to published sea-level curves for the Early Silurian. [ABSTRACT FROM AUTHOR]

Based on the Shidi-1 drill core, this paper presents new and highly time resolved carbon isotope data (δ13C carb) for the Early Ordovician through Early Silurian of the Yangtze Platform, South China. Five carbon isotopic shifts (C1-C5) through the late Tremadocian to the Katian have been recognized in the Shidi-1 drill core recordings. Together with previously published isotope data, a composite carbon isotope curve for the Yangtze platform, permits the identification of a continuous Ordovician carbon isotope trend with five prominent carbon isotope shifts; including the TSICE, the Late Tremadocian positive Isotopic Carbon Excursion (LTICE, named herein), the Late Floian Rise, the MDICE and the Pagoda Isotopic Carbon Excursion (PICE, named herein). The identification and documentation of these anomalies further strengthen the regional and global correlation of the Ordovician succession on the Yangtze platform. The long-term trend in carbon isotopes indicates that organic carbon burial increased gradually throughout the Great Biodiversification Event (GOBE). A tipping point is also marked by the Dapingian-Darriwilian border, which is followed by a notable shift in the environment and creatures in the middle Darriwilian. • A continuous high-resolution δ13C carb curve for nearly the whole Ordovician of South China. • Six prominent and globally comparable carbon isotope shifts have been recognized. • Complied δ13C carb data suggest the important turnover of organisms and environment in the Darriwilian. • The δ13C carb values suggest the increased burial rates of organic matter throughout the Ordovician related to GOBE. [ABSTRACT FROM AUTHOR]

[Display omitted] • We present the first high-resolution Cambrian/Ordovician transition δ13C carb chemostratigraphy in the Eastern North China Platform. • The carbon isotope chemostratigraphy of the Yaowangshan section refines the correlation between North China and other palaeocontinents. • The Cambrian/Ordovician boundary was constrained by the combination of Cordylodus lindstromi Zone and the rising limb of the COTICE in the Yaowangshan section. Revised conodont biostratigraphy and new carbon isotope data through the Cambrian/Ordovician transition are presented for the Yaowangshan section in the eastern North China Platform. Eight conodont zones are recognized, including the Proconodontus muelleri Zone, Eoconodontus Zone, Cordylodus proavus Zone, C. caboti Zone, C. intermedius Zone, C. lindstromi Zone, C. angulatus Zone, and Rossodus manitouensis Zone, in ascending order. The Eoconodontus Zone can be subdivided into the E. notchpeakensis Subzone and the overlying Cambrooistodus minutus Subzone. The new δ13C carb data from the Chaomidian Formation are well constrained by the conodont biozonation and indicate pronounced carbon excursions and spike, Top of Cambrian Excursion (TOCE), Cordylodus proavus spike (CPS), and Cambrian–Ordovician Transition Isotopic Carbon Excursion (COTICE). The isotopic excursions are generally consistent with those of other sections in North China, South China, Tarim, North America, Argentina, and Baltica. [ABSTRACT FROM AUTHOR]

Available data on the temporal and geographical distribution of Middle–early Late Ordovician trilobites in South China were reviewed under a high-resolution biostratigraphical framework to investigate the diversity dynamics and explain the faunal turnover and radiation pattern of trilobites during the Middle Ordovician. Three macroevolutionary phases are recognized on the basis of the diversity changes at taxonomic levels. Cluster analysis shows three trilobite groups, two distinct trilobite faunas and three faunal turnovers through nine time slices. Three trilobite groups (Groups A, B and C) are coupled with three macroevolutionary phases, and characterized by different proportions of the Whiterock Fauna. Two distinct trilobite faunas (Early–Middle Ordovician and Late Ordovician Trilobite Faunas) and three faunal turnovers could be recognized at different similarity coefficients, their replacements were mainly affected by changes of sea level and substrate conditions. The trilobite radiation was manifested by the development, expansion and domination of the Whiterock Fauna (part of the Paleozoic Evolutionary Fauna) through the Middle Ordovician. The first diversity acme of trilobites occurred during the Dapingian–early Darriwilian, while the radiation centre gradually shifted from inner platform to outer platform environments. From the end Darriwilian onwards, elements of the Whiterock Fauna had further developed and dominated all environmental settings from the inner platform to the lower slope, coinciding with the second and more extensive radiation of trilobites in South China. Two phases of radiation may have been directly triggered by two major transgressions during the late Dapingian–early Darriwilian and the late Darriwilian–early Sandbian respectively. In addition, climate cooling and various substrate conditions, as well as the increased oxygen levels in the atmosphere and marine water, nutrients and tectonic movements during the Middle Ordovician may have provided essential conditions for the trilobite radiation. • Three macroevolutionary phases of South China trilobites based on diversity changes. • Heatmap of trilobites based on cluster analysis shows trilobite groups and faunal turnovers. • Development, expansion and domination of the Whiterock Fauna along environmental gradients. • Status of the Whiterock Fauna in the macroevolution of the Ordovician trilobite and Paleozoic Fauna. • Trilobite radiations of South China were closely related to sea level changes. [ABSTRACT FROM AUTHOR]