Terreneuvian bio- and chemostratigraphy of the South Sichuan Region (South China)

2021 ◽  
pp. jgs2020-167
Author(s):  
Ben Yang ◽  
Michael Steiner
Keyword(s):  
Carbon Isotope ◽  
South China ◽  
Cambrian Explosion ◽  
The South ◽  
Yangtze Craton ◽  
Content Type ◽  
Link Type ◽  
Small Shelly Fossils ◽  
Assemblage Zone ◽  
Supplementary Material

Classical sections, such as the Maidiping and Daqiao Mine sections of South Sichuan (China), expose early Cambrian deposits that are crucial for understanding the biological and environmental evolution of Yangtze Craton. These sequences are rich in Terreneuvian small shelly fossils, which can be assigned to assemblages I and III from South China. The Anabarites trisulcatus– Protohertzina anabarica Assemblage Zone (Assemblage I) is recognized at the lower Maidiping Formation. The second assemblage (Paragloborilus subglobosus – Purella squamulosa Assemblage Zone) cannot be verified in South Sichuan, although previous reports claimed its existence based on the occurrence of Paragloborilus subglobosus. The third assemblage (Watsonella crosbyi Assemblage Zone) is confirmed in the upper Maidiping Formation. The abundant bioclasts in this interval indicate abrasions and bioerosions by winnowing or starved sedimentation. Carbon isotope values from the Maidiping section present no negative excursion at the presumed Ediacaran–Cambrian transition. A positive carbon isotope excursion is observed in the upper Maidiping Formation (Assemblage III) which is correlated to the ZHUCE excursion in the Dahai Member of eastern Yunnan. The shallow water deposits of South Sichuan can be correlated with the South China, western Mongolia and Siberia successions based on biozonations and carbon isotope trends.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosionSupplementary material:https://doi.org/10.6084/m9.figshare.c.5326834

scholarly journals Actinomadura craniellae sp. nov., isolated from a marine sponge in the South China Sea

2019 ◽  
Vol 69 (4) ◽  
pp. 1207-1212 ◽  
Author(s):  
Lei Li ◽  
Qi-hang Xu ◽  
Xiao-tian Wang ◽  
Hou-wen Lin ◽  
Yan-hua Lu
Keyword(s):  
South China Sea ◽  
South China ◽  
Marine Sponge ◽  
Type Species ◽  
The South China Sea ◽  
Diaminopimelic Acid ◽  
The South ◽  
Content Type ◽  
China Sea ◽  
Link Type

A novel marine actinomycete, designated LHW63021T, was isolated from a marine sponge, genus Craniella, collected in the South China Sea. A polyphasic approach was applied to characterize the taxonomic position of this strain. The strain was found to have scarce aerial mycelia that differentiated into spore chains. The cell-wall hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid. Glucose, galactose, mannose and madurose were found in the whole-cell hydrolysates. The dominant polar lipids were phosphatidylinositol and diphosphatidylglycerol. MK-9(H6) and MK-9(H8) were the predominant menaquinones. The major fatty acids were iso-C16 : 0, iso-C18 : 0, 10-methyl C17 : 0 and C18 : 1 ω9c. The DNA G+C content based on the draft genome sequence was 72.0 mol%. 16S rRNA gene sequence analysis indicated that strain LHW63021T was a member of the genus Actinomadura and had the highest similarity to Actinomadura echinospora DSM 43163T (97.3 %). Phylogenetic trees supported their close relationship. The average nucleotide identity and digital DNA–DNA hybridization values between the whole genome sequences of strain LHW63021T and A. echinospora DSM 43163T were 79.13 and 23.20 %, respectively. The evidence from the polyphasic study shows that strain LHW63021T represents a novel species of the genus Actinomadura , for which the name Actinomadura craniellae sp. nov. is proposed. The type strain is LHW63021T (=DSM 106125T=CCTCC AA 2018015T).

Palaeolatitudinal distribution of the Ediacaran macrobiota

2021 ◽  
pp. jgs2021-030
Author(s):  
Catherine E. Boddy ◽  
Emily G. Mitchell ◽  
Andrew Merdith ◽  
Alexander G. Liu
Keyword(s):  
Taxonomic Composition ◽  
Supplementary Information ◽  
Cambrian Explosion ◽  
Content Type ◽  
Link Type ◽  
Environmental Perturbations ◽  
Significant Difference ◽  
Evolutionary Trajectories ◽  
Cambrian Radiation ◽  
Supplementary Material

Macrofossils of the late Ediacaran Period (c. 579–539 Ma) document diverse, complex multicellular eukaryotes, including early animals, prior to the Cambrian radiation of metazoan phyla. To investigate the relationships between environmental perturbations, biotic responses and early metazoan evolutionary trajectories, it is vital to distinguish between evolutionary and ecological controls on the global distribution of Ediacaran macrofossils. The contributions of temporal, palaeoenvironmental and lithological factors in shaping the observed variations in assemblage taxonomic composition between Ediacaran macrofossil sites are widely discussed, but the role of palaeogeography remains ambiguous. Here we investigate the influence of palaeolatitude on the spatial distribution of Ediacaran macrobiota through the late Ediacaran Period using two leading palaeogeographical reconstructions. We find that overall generic diversity was distributed across all palaeolatitudes. Among specific groups, the distributions of candidate ‘Bilateral’ and Frondomorph taxa exhibit weakly statistically significant and statistically significant differences between low and high palaeolatitudes within our favoured palaeogeographical reconstruction, respectively, whereas Algal, Tubular, Soft-bodied and Biomineralizing taxa show no significant difference. The recognition of statistically significant palaeolatitudinal differences in the distribution of certain morphogroups highlights the importance of considering palaeolatitudinal influences when interrogating trends in Ediacaran taxon distributions.Supplementary material: Supplementary information, data and code are available at https://doi.org/10.6084/m9.figshare.c.5488945Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosion

Brevibacillus marinus sp. nov., a thermophilic bacterium isolated from deep sea sediment in the South China Sea

2021 ◽  
Vol 71 (12) ◽  
Author(s):  
Ke-Xin Wang ◽  
Cun Li ◽  
Yuan-Qiu He ◽  
Lin-Qing Cui ◽  
Rou-Wen Chen ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Thermophilic Bacterium ◽  
The South China Sea ◽  
Diaminopimelic Acid ◽  
The South ◽  
Circular Chromosome ◽  
Content Type ◽  
China Sea ◽  
Link Type

A novel thermophilic bacterium, designated SCSIO 07484T, was isolated from marine sediment sampled in the South China Sea. Growth occurred at 30–60 °C, pH 6.0–8.0 and in the presence of 0–3 % (w/v) NaCl. Cells of strain SCSIO 07484T were rod-shaped and flagellum-forming. No soluble pigment was observed. The phylogenetic analysis of the 16S rRNA gene sequences indicated that SCSIO 07484T belonged to the family Paenibacillaceae and clustered with members of the genus Brevibacillus in the phylogenetic trees with less than 96.2 % similarities. The cell wall contained meso-diaminopimelic acid. Whole-cell hydrolysates contained arabinose, glucose and ribose. The predominant menaquinone was MK-7. Major fatty acids were iso-C16 : 0, iso-C15 : 0, C16 : 0 and iso-C14 : 0. Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylmonomethylethanolamine were its diagnostic polar lipids. The whole genome size of strain SCSIO 07484T was 4 079 826 bp with a DNA G+C content of 56.2 mol%, including one circular chromosome of 3 978392 bp and one plasmid of 101434 bp. Based on the polyphasic analysis of strain SCSIO 07484T, it is considered to represent a novel species of the genus Brevibacillus , for which the name Brevibacillus marinus sp. nov. is proposed with the type strain SCSIO 07484T (=DSM 106769T=CGMCC 1.15814T).

Lowermost Cambrian acritarchs from the Yanjiahe Formation, South China: implication for defining the base of the Cambrian in the Yangtze Platform

2017 ◽  
Vol 154 (6) ◽  
pp. 1217-1231 ◽  
Author(s):  
SOO YEUN AHN ◽  
MAOYAN ZHU
Keyword(s):  
Carbon Isotope ◽  
South China ◽  
Yangtze Platform ◽  
Small Shelly Fossils ◽  
Temporal Relationships ◽  
Assemblage Zone ◽  
Stratigraphic Range

AbstractTheAsteridium–Heliosphaeridium–Comasphaeridium(AHC) acritarch assemblage is composed of common organic-walled microfossils in the basal Cambrian chert–phosphorite units in South China, indicating that the AHC assemblage can be a useful biostratigraphic tool for the Ediacaran–Cambrian boundary successions in the Yangtze Platform. To test the validity of the AHC acritarch assemblage as a biostratigraphic tool, the stratigraphic range of the AHC acritarch assemblage was confirmed, and its spatial and temporal relationships to other bio- and chemostratigraphic tools were analysed in the Yanjiahe Formation, Yangtze Gorges area, South China. The result shows that the AHC assemblage temporally correlates to theAnabarites trisulcatus–Protohertzina anabaricaAssemblage Zone, and spatially correlates to the large negative carbon isotope anomaly of the lowermost Cambrian (BACE) in the Yanjiahe Formation. This implies that the radiation of phytoplankton occurred slightly before the radiation of the small shelly fossils, and the AHC acritarch assemblage can be another important chronological reference to the lowermost Cambrian successions in South China, and potentially to global correlations.

scholarly journals Puteibacter caeruleilacunae gen. nov., sp. nov., a facultatively anaerobic bacterium isolated from Yongle Blue Hole in the South China Sea

2020 ◽  
Vol 70 (3) ◽  
pp. 1623-1629 ◽  
Author(s):  
Wen Sun ◽  
Tianyu Fu ◽  
Chao Jia ◽  
Liang Fu ◽  
Shun Zhou ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
The South China Sea ◽  
The South ◽  
Content Type ◽  
China Sea ◽  
Link Type ◽  
Facultatively Anaerobic ◽  
Blue Hole ◽  
The Family

Blue holes are unique geomorphological units characterized by steep redox and biogeochemical gradients. Yongle Blue Hole is located on the largest atoll (Yongle Atoll) of the western Xisha Islands in the South China Sea. A Gram-stain-negative, facultatively anaerobic, non-motile, non-flagellated marine bacterium with creamy white colonies, designated JC036T, was isolated from Yongle Blue Hole. Cells were short-rod-shaped and catalase-negative. 16S rRNA gene sequence analysis showed that sequence similarities were lower than 91.6 % against all validly named species in the family Prolixibacteraceae ; a reconstructed phylogenetic tree indicated that strain JC036T formed a lineage with strains in the family Prolixibacteraceae . Growth occurred at 4–37 °C (optimum, 28 °C), at pH 5.0–9.0 (optimum, 7.0) and in the presence of 2–6 % (w/v) NaCl (optimum, 3 %). The prevalent isoprenoid quinone of strain JC036T was menaquinone-7 (MK-7). Iso-C15 : 0 and iso-C17 : 0 3-OH were the predominant fatty acids. The major polar lipids included a phospholipid, phosphatidylethanolamine, an aminophospholipid and four unidentified lipids. The genomic DNA G+C content of strain JC036T was 37.8 mol%. Based on physiological and biochemical characteristics and whole genome comparisons, we propose a new genus and species, Puteibacter caeruleilacunae gen. nov., sp. nov., within the family Prolixibacteraceae . The type strain of Puteibacter caeruleilacunae is JC036T (=JCM 33128T=MCCC 1K03579T). From this study, a deeper understanding of the community of the microorganism and their roles in biogeochemical cycles, especially anaerobic bacteria, is provided.

scholarly journals Nitrincola iocasae sp. nov., a bacterium isolated from sediment collected at a cold seep field in the South China Sea

2020 ◽  
Vol 70 (9) ◽  
pp. 4897-4902 ◽  
Author(s):  
Huan Zhang ◽  
Hao Wang ◽  
Hao Chen ◽  
Qinglei Sun ◽  
Zhaoshan Zhong ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Type Species ◽  
The South China Sea ◽  
Cold Seep ◽  
The South ◽  
Content Type ◽  
China Sea ◽  
Link Type ◽  
A Genome

A novel bacterium, designated strain KXZD1103T, was isolated from sediment collected at a cold seep field of the Formosa Ridge in the South China Sea. Cells were Gram-stain-negative, facultatively anaerobic, motile, oxidase- and catalase-positive, and grew optimally at 28 °C, pH 6.0–pH 7.0 and in the presence of 1–3 % (w/v) NaCl. The major cellular fatty acids were summed feature 8 (C18 : 1  ω7c/C18 : 1  ω6c), summed feature 3 (C16 : 1  ω7c/C16 : 1  ω6c) and C16 : 0. The major respiratory ubiquinone was Q-8. The predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Analysis of 16S rRNA gene sequences revealed that strain KXZD1103T grouped with members of the genus Nitrincola , with Nitrincola lacisaponensis 4CAT (98.1 % sequence similarity) and Nitrincola schmidtii R4-8T (97.7 %) as its closest neighbours. Genome sequencing revealed a genome size of 4.17 Mb and a DNA G+C content of 50.1 %. Genomic average nucleotide identity values for strain KXZD1103T with the type strains within the genus Nitrincola ranged from 71.0 to 75.7 %, while the in silico DNA–DNA hybridization values for strain KXZD1103T with these strains ranged from 16.1 to 21.6 %. On the basis of the results of phylogenetic, phenotypic and chemotaxonomic analyses, strain KXZD1103T is considered to represent a novel species of the genus Nitrincola , for which the name Nitrincola iocasae sp. nov. is proposed. The type strain is KXZD1103T (=KCTC 72678T=MCCC 1K04283T).

scholarly journals Tabelliscolex (Cricocosmiidae: Palaeoscolecidomorpha) from the early Cambrian Chengjiang Biota, and the evolution of seriation in Ecdysozoa

2021 ◽  
pp. jgs2021-060
Author(s):  
Xiaomei Shi ◽  
Richard J. Howard ◽  
Gregory D. Edgecombe ◽  
Xianguang Hou ◽  
Xiaoya Ma
Keyword(s):  
Phylogenetic Analyses ◽  
Sensu Stricto ◽  
Cambrian Explosion ◽  
Early Cambrian ◽  
Content Type ◽  
Link Type ◽  
Stem Group ◽  
New Material ◽  
Supplementary Material ◽  
Chengjiang Biota

Cricocosmiidae is a clade of palaeoscolecid-like worms from the Chengjiang Biota, China (Cambrian Stage 3). In contrast to palaeoscolecids sensu stricto, which exhibit tessellating micro-plate trunk ornamentation, cricocosmiids possess larger, serially repeated sets of trunk sclerites bearing resemblance to lobopodian trunk sclerites (e.g., Microdictyon spp.). Cricocosmiidae were therefore proposed as stem-group Panarthropoda in some studies but are recovered as stem-group Priapulida in most phylogenetic analyses. The affinity of cricoscosmiids within Ecdysozoa is therefore of much interest, as is testing the homology of these seriated structures. We report four new specimens of the rare cricocosmiid Tabelliscolex hexagonus, yielding new details of the ventral trunk projections, sclerites and proboscis. New data confirm T. hexagonus possessed paired ventral trunk projections in a consistent seriated pattern, which is also reported from new material of Cricocosmia jinningensis (Cricocosmiidae) and Mafangscolex yunnanensis (Palaeoscolecida sensu stricto). Even when the seriated sclerites and ventral projections of cricocosmiids are coded as homologous with the seriated trunk sclerites and paired appendages, respectively, of lobopodian panarthropods, our tree searches indicate they are convergent. Cricocosmiidae is nested within a monophyletic “Palaeoscolecida sensu lato” clade (Palaeoscolecidomorpha nov.) in stem-group Priapulida. Our study indicates that morphological seriation has independent origins in Scalidophora and Panarthropoda.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosionSupplementary material:https://doi.org/10.6084/m9.figshare.c.5551565

Spatial heterogeneity of redox-sensitive trace metal enrichments in upper Ediacaran anoxic black shales

2021 ◽  
pp. jgs2020-234
Author(s):  
Chengsheng Jin ◽  
Chao Li ◽  
Thomas J. Algeo ◽  
Guochang Wang ◽  
Wei Shi ◽  
...  
Keyword(s):  
Spatial Heterogeneity ◽  
Water Mass ◽  
Significant Degree ◽  
Black Shales ◽  
Redox Conditions ◽  
Cambrian Explosion ◽  
Content Type ◽  
Oxygen Levels ◽  
Link Type ◽  
Supplementary Material

The Ediacaran radiation of metazoans is widely thought to have been triggered by an increase in atmospheric and oceanic oxygen levels. Although supported by other proxies, rising oxygen levels were deduced to a significant degree from sedimentary enrichments of redox-sensitive trace elements (RSTEs). However, some organic-rich shales of this period show only minor enrichments in RSTEs, leaving the significance of RSTE data for palaeo-oxygenation interpretations in doubt. We measured and compiled proxies for marine redox conditions (Fe species, RSTEs), total organic carbon (TOC) and water mass restriction (Mo/TOC and Co × Mn v. Cd/Mo) in the intra-shelf Jiulongwan and basinal Sandu sections of the Nanhua Basin in South China. Compared with the same proxies from coeval sections in the Nanhua Basin and globally, our results document a strong spatial heterogeneity of RSTE enrichments in anoxic black shales during the late Ediacaran. We infer that RSTE enrichments were strongly influenced by local factors, such as basinal restriction, seawater RSTE concentrations, and differential elemental responses to redox conditions and other influences. The broader significance of our findings is that they highlight the difficulty of investigating global redox conditions based on an analysis of local RSTE proxies within a single depositional basin or a limited number of study sections.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosionSupplementary material: Tables S1–S3 are available at https://doi.org/10.6084/m9.figshare.c.5325047

Fuxianhuiids are mandibulates and share affinities with total-group Myriapoda

2021 ◽  
pp. jgs2020-246 ◽  
Author(s):  
Cédric Aria ◽  
Fangchen Zhao ◽  
Maoyan Zhu
Keyword(s):  
Phylogenetic Analysis ◽  
Sister Group ◽  
Cambrian Explosion ◽  
Content Type ◽  
Total Group ◽  
Link Type ◽  
Supplementary Material ◽  
Ecological Success ◽  
Chengjiang Biota ◽  
Additional Support

In spite of their unrivalled ecological success, the origins of terrestrial mandibulates have long remained virtually unknown. In recent years, claims have been made based on phylogenetic results that fuxianhuiids, iconic fossils of the Chengjiang biota and purported basal euarthropods, were in fact mandibulates, allied with the problematic euthycarcinoids as the closest sister-group to Mandibulata or even stem myriapods. A re-examination of euthycarcinoid mouthparts has since brought additional support to this view. Here, we reinvestigated the anterior anatomy of the Cambrian euarthropod Fuxianhuia and its relatives. We demonstrate that the fuxianhuiid head is that of a mandibulate, sharing similarities with hymenocarines, including a limbless intercalary segment. The hypostome is a sub-triangular sclerite partially fused but anatomically independent from a large, bilobed labral plate, as observed in many extant mandibulate taxa as well as euthycarcinoids. The so-called ‘specialized post-antenn(ular) appendages' are therefore the mandibles, with a tripartite palp and large dented gnathal lobe partially covered by the hypostome-labrum complex. Under a ‘deep split' phylogenetic scenario, Fuxianhuia and its relatives are here resolved as sister-group to crown Mandibulata.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosionSupplementary material: Additional remarks on terminology, morphological interpretations and a list of modified/new characters used for the phylogenetic analysis are available at https://doi.org/10.6084/m9.figshare.c.5305042

scholarly journals Devosia marina sp. nov., isolated from deep seawater of the South China Sea, and reclassification of Devosia subaequoris as a later heterotypic synonym of Devosia soli

2020 ◽  
Vol 70 (5) ◽  
pp. 3062-3068 ◽  
Author(s):  
Yang Liu ◽  
Juan Du ◽  
Jun Zhang ◽  
Qiliang Lai ◽  
Zongze Shao ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
South China Sea ◽  
South China ◽  
Type Species ◽  
The South China Sea ◽  
The South ◽  
Deep Seawater ◽  
Content Type ◽  
China Sea ◽  
Link Type

A Gram-stain-negative, aerobic, rod-shaped and motile bacterial strain, designated L53-10-65T, was isolated from deep seawater of the South China Sea. Strain L53-10-65T was found to grow at 4–41 °C (optimum, 28 °C), at pH 5.0–9.0 (pH 7.0–8.0) and in 0–7 % (w/v) NaCl (2 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain L53-10-65T fell within the genus Devosia , with the highest similarity to Devosia indica IO390501T (98.4 %), followed by ‘ Devosia lucknowensis ’ L15T (97.7 %) and Devosia riboflavina IFO 13584T (96.8 %). The digital DNA–DNA hybridization (dDDH) values between strain L53-10-65T and the three relatives above were 43.7, 21.5 and 20.9 %, respectively; the average nucleotide identity (ANI) values were 91.3, 78.4 and 76.8 %, respectively. These values were below the 70 % dDDH and 95–96 % ANI thresholds for bacterial species delineation. The major cellular fatty acids of strain L53-10-65T were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C18 : 1 ω7c 11-methyl and C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and glycolipids. The respiratory quinone was identified as Q-10. The DNA G+C content of strain L53-10-65T was 61.3 mol%. Based on the results of phylogenetic analysis and distinctive phenotypic characteristics, strain L53-10-65T is concluded to represent a novel species of the genus Devosia , for which the name Devosia marina sp. nov. is proposed. The type strain of the species is L53-10-65T (=MCCC 1A05139T=KCTC 72888T). Moreover, we propose that Devosia subaequoris is a later heterotypic synonym of Devosia soli based on the present results.

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