The influence of the Late Devonian Kellwasser events on deep-water ecosystems: Evidence from palaeontological and geochemical records from South China

2018 ◽  
Vol 504 ◽  
pp. 60-74 ◽  
Author(s):  
Cheng Huang ◽  
Junjun Song ◽  
Jun Shen ◽  
Yiming Gong
2007 ◽  
Vol 26 (2) ◽  
pp. 169-191 ◽  
Author(s):  
Aihua Yuan ◽  
Sylvie Crasquin-Soleau ◽  
Qinglai Feng ◽  
Songzhu Gu

Abstract. A very diverse ostracod fauna was discovered in the latest Permian strata of the Dongpan section, southwestern Guangxi, South China. Fifty-one species belonging to twenty-eight genera were identified and described, including two new species (Bairdia dongpanensis n. sp. and Spinomicrocheilinella anterocompressa n. sp). This type of assemblage, with nineteen palaeopsychrospheric species and four pelagic species, is the first world-wide deep-water ostracod fauna reported from the latest Permian strata and the first one recorded in the Permian of China. The palaeoenvironmental analysis allows one to propose an evaluation of the bathymetry variation along the Dongpan section.


2009 ◽  
Vol 33 (2) ◽  
pp. 163-183 ◽  
Author(s):  
Zhong-Qiang Chen ◽  
G. R. Shi ◽  
Yongqun Gao ◽  
Jinnan Tong ◽  
Fengqing Yang ◽  
...  

2015 ◽  
Vol 12 (23) ◽  
pp. 6869-6880 ◽  
Author(s):  
M. Wall ◽  
F. Ragazzola ◽  
L. C. Foster ◽  
A. Form ◽  
D. N. Schmidt

Abstract. Cold-water corals are important habitat formers in deep-water ecosystems and at high latitudes. Ocean acidification and the resulting change in aragonite saturation are expected to affect these habitats and impact coral growth. Counter to expectations, the deep water coral Lophelia pertusa has been found to be able to sustain growth even in undersaturated conditions. However, it is important to know whether such undersaturation modifies the skeleton and thus its ecosystem functioning. Here we used Synchrotron X-Ray Tomography and Raman spectroscopy to examine changes in skeleton morphology and fibre orientation. We combined the morphological assessment with boron isotope analysis to determine if changes in growth are related to changes in control of calcification pH. We compared the isotopic composition and structure formed in their natural environment to material grown in culture at lower pH conditions. Skeletal morphology is highly variable but shows no distinctive differences between natural and low pH conditions. Raman investigations found no difference in macromorphological skeletal arrangement of early mineralization zones and secondary thickening between the treatments. The δ11B analyses show that L. pertusa up-regulates the internal calcifying fluid pH (pHcf) during calcification compared to ambient seawater pH and maintains a similar elevated pHcf at increased pCO2 conditions. We suggest that as long as the energy is available to sustain the up-regulation, i.e. individuals are well fed, there is no detrimental effect to the skeletal morphology.


2000 ◽  
Vol 74 (3) ◽  
pp. 444-463 ◽  
Author(s):  
Xueping Ma ◽  
Jed Day

The cyrtospiriferid brachiopod genus Tenticospirifer Tien, 1938, is revised based on restudy of the type species from the Frasnian (Late Devonian) of the Russian Platform. As revised the genus includes cyrtospiriferid species with pyramidal ventral valves, catacline ventral interareas, a narrow delthyrium, few sinal plications, and lack a median dorsal septum and pseudodeltidium. All species retained in the genus are of Givetian and Frasnian age. All Famennian age species described from South China and North America are rejected from the genus. It appears that Tenticospirifer evolved during the early Givetian in western Europe and remained endemic to that region during the remainder of the Givetian. Successive migrations of Tenticospirifer from eastern Laurussia to North America, then to South China and possibly Australia, coincided with middle and late Frasnian eustatic sea level rises, respectively. The North American species Spirifera cyrtinaformis Hall and Whitfield, 1872, and related species identified as Tenticospirifer by North American workers, are reassigned to Conispirifer Lyashenko, 1985. Its immigration to and widespread dispersal in carbonate platforms of western Laurussia, northern Gondwana and tropical island arcs (?) coincided with a major late Frasnian eustatic sea level rise. The new family Conispiriferidae is proposed with Conispirifer Lyashenko, 1985, selected as the type genus. The new family also includes the new genus Pyramidaspirifer with Platyrachella alta Fenton and Fenton, 1924, proposed as the type species. The affinity of the new family remains uncertain pending restudy of key genera currently included in the Superfamily Cyrtospiriferoidea. Available data from the Devonian brachiopod literature indicate that species of Pyramidaspirifer are restricted to late Frasnian deposits of central and western North America.


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