scholarly journals Sedimentary factories and ecosystem change across the Permian-Triassic Critical Interval (P-TrCI) – insights from the Xiakou area (South China)

2020 ◽  
Author(s):  
Yu Pei ◽  
Jan-Peter Duda ◽  
Joachim Reitner

AbstractThe Permian-Triassic mass extinction included a potentially catastrophic decline of biodiversity, but ecosystem change across this event remains poorly characterized. Here we reconstruct sedimentary factories and ecosystem change across the Permian-Triassic Critical Interval (P-TrCI) in the Xiakou area (South China). Six microfacies (MF) were classified. The succession begins with a eukaryote-controlled carbonate factory (MF-1) that passes upward into an organomineralization-dominated carbonate factory (MF-2–3). Organic-rich marls atop these units reflect carbonate factory collapse (MF-4). Organomineralization-driven carbonate formation restarts prior to the Permian-Triassic boundary (MF-5) and subsequently develops into a mixed carbonate factory where organomineralization and biomineralization are almost equally important (MF-6). MF-1 reflects oxygenated shallow water environments. In contrast, MF-2–6 were all deposited in somewhat deeper environments, some of which episodically exhibited elevated salinities, oxygen depletion, and, possibly, euxinic conditions. Our results demonstrate that distinct changes in carbonate production styles, biodiversity, and environmental conditions are not synchronous at Xiakou. Furthermore, the Xiakou record is strikingly different to that of other localities, even from the same area (e.g., the Global Stratotype Section and Point section at Meishan). Together, these findings highlight the enormous complexity of the P-TrCI and calls simplified views of the Permian-Triassic mass extinction into question.

PalZ ◽  
2020 ◽  
Author(s):  
Yu Pei ◽  
Jan-Peter Duda ◽  
Joachim Reitner

Abstract The Permian–Triassic mass extinction included a potentially catastrophic decline of biodiversity, but ecosystem change across this event remains poorly characterized. Here we reconstruct sedimentary factories and ecosystem change across the Permian–Triassic Critical Interval (P–TrCI) in the Xiakou area (South China). Six microfacies (MF) were classified. The succession begins with a eukaryote-controlled carbonate factory (MF-1) that passes upward into an organomineralization-dominated carbonate factory (MF-2–3). Organic-rich marls atop these units reflect carbonate factory collapse (MF-4). Organomineralization-driven carbonate formation restarts prior to the Permian–Triassic boundary (MF-5) and subsequently develops into a mixed carbonate factory where organomineralization and biomineralization are almost equally important (MF-6). MF-1 reflects oxygenated shallow water environments. In contrast, MF-2–6 were all deposited in somewhat deeper environments, some of which episodically exhibited elevated salinities, oxygen depletion, and, possibly, euxinic conditions. Our results demonstrate that distinct changes in carbonate production styles, biodiversity, and environmental conditions are not synchronous at Xiakou. Furthermore, the Xiakou record is strikingly different to that of other localities, even from the same area (e.g., the Global Stratotype Section and Point section at Meishan). Together, these findings highlight the enormous complexity of the P–TrCI and calls simplified views of the Permian–Triassic mass extinction into question.


Paleobiology ◽  
2011 ◽  
Vol 37 (1) ◽  
pp. 157-167 ◽  
Author(s):  
Conghui Xiong ◽  
Qi Wang

Diversity dynamics of the Permian–Triassic land plants in South China are studied by analyzing paleobotanical data. Our results indicate that the total diversity of land-plant megafossil genera and species across the Permian/Triassic boundary (PTB) of South China underwent a progressive decline from the early Late Permian (Wuchiapingian) to the Early-Middle Triassic. In contrast, the diversity of land-plant microfossil genera exhibited only a small fluctuation across the PTB of South China, showing an increase at the PTB. Overall, land plants across the PTB of South China show a greater stability in diversity dynamics than marine faunas. The highest extinction rate (90.91%) and the lowest origination rate (18.18%) of land-plant megafossil genera occurred at the early Early Triassic (Induan), but the temporal duration of the higher genus extinction rates (>60%) in land plants was about 23.4 Myr, from the Wuchiapingian to the early Middle Triassic (Anisian), which is longer than that of the coeval marine faunas (3–11 Myr). Moreover, the change of genus turnover rates in land-plant megafossils steadily fluctuated from the late Early Permian to the Late Triassic. More stable diversity and turnover rate as well as longer extinction duration suggest that land plants near the PTB of South China may have been involved in a gradual floral reorganization and evolutionary replacement rather than a mass extinction like those in the coeval marine faunas.


2009 ◽  
Vol 2 (4) ◽  
pp. 417-431
Author(s):  
Yin Hongfu ◽  
Huang Siji ◽  
Zhang Kexin ◽  
Yang Fengqing ◽  
Ding Meihua ◽  
...  

2021 ◽  
pp. 1-53
Author(s):  
Demir Altıner ◽  
Jonathan L. Payne ◽  
Daniel J. Lehrmann ◽  
Sevinç Özkan-Altıner ◽  
Brian M. Kelley ◽  
...  

Abstract Foraminifera are important components of tropical marine benthic ecosystems and their recovery pattern from the end-Permian mass extinction can yield insights into the Mesozoic history of this group. Here we report the calcareous and agglutinated foraminifera recovered from five measured stratigraphic sections on the Great Bank of Guizhou, an uppermost Permian to Upper Triassic isolated carbonate platform in the Nanpanjiang Basin, south China. The material contains >100 Triassic species, including three that are newly described (Arenovidalina weii n. sp., Meandrospira? enosi n. sp., and Spinoendotebanella lehrmanni n. gen., n. sp.), ranging from Griesbachian (Induan) to Cordevolian (Carnian) age. The species belong to the classes Miliolata, Textulariata, Fusulinata, Nodosariata, and to an unknown class housing all aragonitic forms of the orders Involutinida and Robertinida. Based on previously established conodont zones and carbon isotope chemostratigraphy, the Griesbachian (early Induan) through Illyrian (late Anisian) interval has been subdivided into 12 foraminiferal zones and two unnamed intervals devoid of foraminifera. Following the extinction at the Permian-Triassic boundary, habitable ecological niches of Griesbachian age were invaded by disaster taxa that subsequently became extinct during the Dienerian (late Induan) and left no younger descendants. The disaster taxa were replaced by Lazarus taxa with Permian origins, which were then decimated by the Smithian-Spathian (mid-Olenekian) boundary crisis. The tempo of recovery appears to have been modulated by environmental changes during the Griesbachian through Smithian that involved both climate change and expansion of anoxic ocean bottom waters. Uninterrupted and lasting recovery of benthic foraminifera did not begin until the Spathian. UUID: http://zoobank.org/2a6e9061-b163-402a-9098-8765a80576b3


2006 ◽  
Vol 143 (3) ◽  
pp. 301-327 ◽  
Author(s):  
ZHONG-QIANG CHEN ◽  
KUNIO KAIHO ◽  
ANNETTE D. GEORGE ◽  
JINNAN TONG

Eight brachiopod species in seven genera are described from the Permian–Triassic boundary beds of South China and northern Italy. The brachiopods from northern Italy are described for the first time and include two new species: Orbicoelia dolomitensis Chen and Spirigerella? teseroi Chen. The Permian affinity of these brachiopods and their stratigraphical position above the extinction horizon demonstrate that they are survivors from the end-Permian mass extinction. The surviving brachiopods from South China, which was located at the eastern margin of the Palaeo-Tethys Ocean, are considerably abundant and diverse and are dominated by geographically widespread generalist elements adapted to a wide variety of environments. They were mostly limited to the Upper Permian to lowest Griesbachian. In contrast, the survivors in northern Italy, which was situated at the western margin of the Palaeo-Tethys, comprise elements ranging from the Carboniferous to Permian or widespread Tethyan genera. These survivors did not occur in the pre-extinction western Tethyan oceans but migrated into this region after the end-Permian extinction event. Disaster taxon Lingula proliferated slightly earlier in western Tethyan oceans than in eastern Tethyan regions following the event. Survival brachiopods from both regions appear to have a generic affinity, although they do not share any species. Both South Chinese and Italian survival faunas support the view that the survival interval is the duration when survivors are dominated by geographically widespread generalist organisms adapted to a wide variety of ecological conditions.


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