Middle Triassic (Anisian) Conodont Biostratigraphy at the Shaiwa Section, Guizhou, South China

Previous studies of conodonts suggested that the upper member of the Xiushan Formation (late Llandovery) corresponds to the Pterospathodus eopennatus Superbiozone, but no data were obtained from the lower member in the Xiushan area. In this study, the entire Xiushan Formation was resampled from the Datianba section in the Xiushan area of Chongqing City on the Yangtze Platform in South China. In total, 40 samples were collected and processed. Fifteen of these samples contained identifiable conodont specimens. The present study indicates that the lower member and main part of the upper member of the Xiushan Formation correspond to the Pterospathodus eopennatus Superbiozone, while the top of the upper member probably correlates with the Pterospathodus celloni Superbiozone.

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Carboniferous conodont biostratigraphy of the Dianzishang section, Zhenning, Guizhou, South China

Geological Magazine ◽

10.1017/s0016756813000344 ◽

2013 ◽

Vol 151 (2) ◽

pp. 311-327 ◽

Cited By ~ 9

Author(s):

YUPING QI ◽

KEYI HU ◽

QIULAI WANG ◽

WEI LIN

Keyword(s):

South China ◽

North American ◽

Primitive Form ◽

Conodont Biostratigraphy ◽

The World ◽

Kasimovian Stage ◽

Moscovian Stage ◽

Stage Boundaries ◽

Serpukhovian Stage ◽

Bashkirian Stage

AbstractA preliminary summary of the lower Visean to uppermost Moscovian (Carboniferous) conodont succession and biostratigraphy of the Dianzishang section in Zhenning, Guizhou, South China is presented. Eleven conodont zones, in ascending order, can be recognized:Gnathodus praebilineatus,Gnathodus bilineatus,Lochriea ziegleri,Declinognathodus noduliferus,Neognathodus symmetricus, ‘Streptognathodus’expansus(primitive form), ‘Streptognathodus’expansus,Mesogondolella donbassica – Mesogondolella clarki,Idiognathodus podolskensis,Swadelinafauna andIdiognathodus swadeizones. The first occurrences ofLochriea ziegleriat the base of the Serpukhovian Stage,Declinognathodus noduliferus noduliferusat the base of the Bashkirian Stage and ‘Streptognathodus’expansusat the base of the Moscovian Stage are recognized. The definitions of these stage boundaries, as well as that of the base of the Kasimovian Stage are discussed. Correlations with the Naqing section in South China, Russian and North American sections, as well as other important sections in the world, are considered.

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Early and Middle Triassic trends in diversity, evenness, and size of foraminifers on a carbonate platform in south China: implications for tempo and mode of biotic recovery from the end-Permian mass extinction

Paleobiology ◽

10.1666/08082.1 ◽

2011 ◽

Vol 37 (3) ◽

pp. 409-425 ◽

Cited By ~ 57

Author(s):

Jonathan L. Payne ◽

Mindi Summers ◽

Brianna L. Rego ◽

Demir Altiner ◽

Jiayong Wei ◽

...

Keyword(s):

South China ◽

Mass Extinction ◽

Evolutionary Dynamics ◽

Middle Triassic ◽

Carbonate Platform ◽

Early Triassic ◽

Data Set ◽

Recovery Pattern ◽

Biotic Recovery ◽

Permian Mass Extinction

Delayed biotic recovery from the end-Permian mass extinction has long been interpreted to result from environmental inhibition. Recently, evidence of more rapid recovery has begun to emerge, suggesting the role of environmental inhibition was previously overestimated. However, there have been few high-resolution taxonomic and ecological studies spanning the full Early and Middle Triassic recovery interval, leaving the precise pattern of recovery and underlying mechanisms poorly constrained. In this study, we document Early and Middle Triassic trends in taxonomic diversity, assemblage evenness, and size distribution of benthic foraminifers on an exceptionally exposed carbonate platform in south China. We observe gradual increases in all metrics through Early Triassic and earliest Middle Triassic time, with stable values reached early in the Anisian. There is little support in our data set for a substantial Early Triassic lag interval during the recovery of foraminifers or for a stepwise recovery pattern. The recovery pattern of foraminifers on the GBG corresponds well with available global data for this taxon and appears to parallel that of many benthic invertebrate clades. Early Triassic diversity increase in foraminifers was more gradual than in ammonoids and conodonts. However, foraminifers continued to increase in diversity, size, and evenness into Middle Triassic time, whereas diversity of ammonoids and conodonts declined. These contrasts suggest decoupling of recovery between benthic and pelagic environments; it is unclear whether these discrepancies reflect inherent contrasts in their evolutionary dynamics or the differential impact of Early Triassic ocean anoxia or associated environmental parameters on benthic ecosystems.

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