A nearshore–offshore trend in acritarch distribution from the Early–Middle Ordovician of the Yangtze Platform, South China

Li, Jun; Servais, Thomas; Yan, Kui; Zhu, Hongtao

doi:10.1016/j.revpalbo.2003.12.005

Cited by 65 publications

(28 citation statements)

References 19 publications

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“…This lithological/facies pattern is not comparable with the pattern of diversity displayed by acritarchs, brachiopods, and trilobites, where these fossil groups reach their maximum diversity in marly and shale-rich intervals (Li et al 2004a, Zhan & Harper 2006, Turvey 2005.…”

Section: Conodont Diversity and Facies Changesmentioning

confidence: 57%

“…The highest conodont diversification in the Early Ordovician shows a parallel to diversity maxima for both acritarchs and brachiopods, which display a similar high peak in the Early Ordovician (Li et al 2004aZhan & Harper 2006). Whether this means that phytoplankton diversity is a prelude to the diversities of other groups (Lehnert et al 2007b) still remains to be investigated.…”

Section: Resultsmentioning

confidence: 99%

“…Observations on the diversity of acritarchs, brachiopods, and trilobites from the Yangtze Platform, including the Yichang Region, are made by Brocke (1997), Brocke et al (2000), Li et al (2004aLi et al ( , 2007, and Turvey (2005). These papers provide a basis for discussing possible causes of variation in the diversification in these fossil groups over time.…”

Section: Yichang Region Central Chinamentioning

confidence: 99%

“…In the Darriwilian the acritarchs were moderately diverse (32) species in the Lenodus antivariabilis Zone (pars stage slice Dw 1) and the diversity increases to 42 species in the Lenodus variabilis Zone. Li et al (2002) related the general pattern of diversity of the acritarchs from the Tremadocian to the Darriwilian to sea-level changes whereas lateral distribution of different assemblages depended on local palaeoecological factors such as distance from the coast and the water depth (Li & Yan 2006, Li et al 2004a.…”

Section: Comparison With Diversity Trends Of Other Fossil Groupsmentioning

confidence: 99%

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Lower and Middle Ordovician conodont diversity of the Yichang Region, Hubei Province, Central China

Wu¹,

Stouge²,

Li³

et al. 2010

Bull. Geosci.

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A survey on the (palaeo-) diversity of the Lower and Middle Ordovician conodont faunas from the Yichang Region, Hubei Province, Central China is presented. Analysis of the number of species through time shows the species richness is cyclical developed in the succession -varying from low to high. One major conodont diversity peak is recorded in the mid to late Floian Stage (Oepikodus evae Zone, stage slice Fl 2, Lower Ordovician), where 33 species are recorded in the lower unit of the Dawan Formation. A smaller but second high diversity is found in the Darriwilian Stage (Lenodus variabilis Zone; stage slice Da 2, Middle Ordovician) with a maximum of 23 species. Secondary, smaller diversification maxima are present in the early Tremadocian, late Tremadocian, early Dapingian and late Darriwilian stages. Current information on acritarchs, brachiopods, and trilobites shows that the highest diversity maximum of conodonts corresponds to a similar high in brachiopod diversity, whereas acritarch and trilobite maximum diversity appear after the conodonts/brachiopods in the region.•

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Section: Conodont Diversity and Facies Changesmentioning

confidence: 57%

Section: Resultsmentioning

confidence: 99%

Section: Yichang Region Central Chinamentioning

confidence: 99%

Section: Comparison With Diversity Trends Of Other Fossil Groupsmentioning

confidence: 99%

See 2 more Smart Citations

Lower and Middle Ordovician conodont diversity of the Yichang Region, Hubei Province, Central China

Wu¹,

Stouge²,

Li³

et al. 2010

Bull. Geosci.

View full text Add to dashboard Cite

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“…In these Chinese Permian sections the Leiosphaeridia are associated with deeper, more open marine waters (Lei et al, 2012). Conversely, studies of early Palaeozoic acritarchs show that, in general, leiospheres, or sphaeromorphs, are most frequent in proximal environments (Li et al, 2004;Stricanne et al, 2004). The leiosphere group might be polyphyletic and some species might have prasinophyte affinities (Colbath and Grenfell, 1995), which complicates their use for environmental reconstructions.…”

Section: Sea-level and Salinity Changesmentioning

confidence: 99%

Salinity changes and anoxia resulting from enhanced run-off during the late Permian global warming and mass extinction event

2018

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Abstract. The late Permian biotic crisis had a major impact on marine and terrestrial environments. Rising CO 2 levels following Siberian Trap volcanic activity were likely responsible for expanding marine anoxia and elevated water temperatures. This study focuses on one of the stratigraphically most expanded Permian-Triassic records known, from Jameson Land, East Greenland. High-resolution sampling allows for a detailed reconstruction of the changing environmental conditions during the extinction event and the development of anoxic water conditions. Since very little is known about how salinity was affected during the extinction event, we especially focus on the aquatic palynomorphs and infer changes in salinity from changes in the assemblage and morphology. The start of the extinction event, here defined by a peak in spore : pollen, indicating disturbance and vegetation destruction in the terrestrial environment, postdates a negative excursion in the total organic carbon, but predates the development of anoxia in the basin. Based on the newest estimations for sedimentation rates, the marine and terrestrial ecosystem collapse took between 1.6 and 8 kyr, a much shorter interval than previously estimated. The palynofacies and palynomorph records show that the environmental changes can be explained by enhanced run-off and increased primary productivity and water column stratification. A lowering in salinity is supported by changes in the acritarch morphology. The length of the processes of the acritarchs becomes shorter during the extinction event and we propose that these changes are evidence for a reduction in salinity in the shallow marine setting of the study site. This inference is supported by changes in acritarch distribution, which suggest a change in palaeoenvironment from open marine conditions before the start of the extinction event to more nearshore conditions during and after the crisis. In a period of sea-level rise, such a reduction in salinity can only be explained by increased run-off. High amounts of both terrestrial and marine organic fragments in the first anoxic layers suggest that high run-off, increased nutrient availability, possibly in combination with soil erosion, are responsible for the development of anoxia in the basin. Enhanced run-off could result from changes in the hydrological cycle during the late Permian extinction event, which is a likely consequence of global warming. In addition, vegetation destruction and soil erosion may also have resulted in enhanced run-off. Salinity stratification could potentially explain the development of anoxia in other shallow marine sites. The input of freshwater and related changes in coastal salinity could also have implications for the interpretation of oxygen isotope records and seawater temperature reconstructions at some sites.

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Biodiversity of Early-Middle Ordovician acritarchs and sea level changes in South China

Yan

2005

Chin.Sci.Bull.

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As the primary producers, acritarchs represent the base of the food chain in the Paleozoic marine ecosystem which links with the evolution of acritarchs. Based on high precision quantitative research, much information about Paleozoic marine ecosystem is provided. A quantitative analysis of Early-Middle Ordovician acritarch diversity changes in the Meitan Formation, Honghuayuan section, Tongzi, Guizhou is made and the the acritarch diversity curves are compared with sea level curves. We found that acritarch diversity changes were related to sea level changes during the Early-Middle Ordovician. Whereas sea level rose, and acritarch diversity also increased. An inshore-offshore model of acritarchs best explains the relative abundance changes of some acritarch taxa in relation to sea level changes.

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A nearshore–offshore trend in acritarch distribution from the Early–Middle Ordovician of the Yangtze Platform, South China

Cited by 65 publications

References 19 publications

Lower and Middle Ordovician conodont diversity of the Yichang Region, Hubei Province, Central China

Lower and Middle Ordovician conodont diversity of the Yichang Region, Hubei Province, Central China

Salinity changes and anoxia resulting from enhanced run-off during the late Permian global warming and mass extinction event

Biodiversity of Early-Middle Ordovician acritarchs and sea level changes in South China

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