Paleobiogeographical extinction patterns of Permian brachiopods in the Asian-western Pacific region

Spatial and temporal variations in biological diversity are critical in understanding the role of biogeographical regulation (if any) on mass extinctions. An analysis based on a latest database of the stratigraphic ranges of 89 Permian brachiopod families, 422 genera, and 2059 species within the Boreal, Paleoequatorial, and Gondwanan Realms in the Asian–western Pacific region suggests two discrete mass extinctions, each possibly with different causes. Using species/family rarefaction analysis, we constructed diversity curves for late Artinskian–Kungurian, Roadian–Wordian, Capitanian, and Wuchiapingian intervals for filtering out uneven sampling intensities. The end-Changhsingian (latest Permian) extinction eliminated 87–90% of genera and 94–96% of species of Brachiopoda. The timing of the end-Changhsingian extinction of brachiopods in the carbonate settings of South China and southern Tibet indicates that brachiopods suffered a rapid extinction within a short interval just below the Permian/Triassic boundary.

In comparison, the end-Guadalupian/late Guadalupian extinction is less profound and varies temporally in different realms. Brachiopods in the western Pacific sector of the Boreal Realm nearly disappeared by the end-Guadalupian but experienced a relatively long-term press extinction spanning the entire Guadalupian in the Gondwanan Realm. The end-Guadalupian brachiopod diversity fall is not well reflected at the timescale used here in the Paleoequatorial Realm because the life-depleted early Wuchiapingian was overlapped by a rapid radiation phase in the late Wuchiapingian. The Guadalupian fall appears to be related to the dramatic reduction of habitat area for the brachiopods, which itself is associated with the withdrawal of seawater from continental Pangea and the closure of the Sino-Mongolian seaway by the and-Guadalupian.

Discovery of late Changhsingian (latest Permian) brachiopod Attenuatella species from South China

Attenuatella mengi sp. nov. and ?Attenuatella sp. from the Talung Formation, southern Guangxi Zhuang Autonomous Region, South China, are described herein. This discovery represents the first report of Attenuatella from the late Changhsingian (latest Permian) in South China and provides evidence that Attenuatella expanded its range from high-latitude cold-water regions to palaeoequatorial warm water areas in the Late Permian. Attenuatella
species appear to have been pseudoplanktonic, judging from their hair-like spinose ornamentation, which could have contributed to the global palaeogeographical distribution of Attenuatella.

Permian soft-sediment deformation structures related to earthquake in the Southern Sydney Basin, Eastern Australia

Sydney Basin is located in the eastern part of Australia, Lachlan Fold Belt, and between the New England Fold Belt. From the Sydney basin at the end of the Late Carboniferous to Middle Triassic experienced back-arc spreading to the foreland basin at different stages: back-arc spreading stage (Carboniferous ), A passive thermal subsidence stage (early in the Permian Berry) and load deflection extruding stage (in Broughton Permian - Triassic). This time at the Sydney basin on the eastern side of the New England Fold Belt for the island Background of the arc. As a result, back-arc in the Permian Basin of the South Sydney basin by the back-arc spreading the eastern side of the arc and trench subduction before the impact of strong seismic activity, the development of a series of earthquake-related seismites to form various types and Seismic activity related to the deformation of soft sediment structure. Permian Basin, South Sydney's soft sediment deformation including cracks in shock-fold, liquefied vein, volcanic sand, load structure, flame Construction, pillow-like structure, spherical structure, pillow Layer structure slump, and so breccia. To which the cracks in shock-fold fibrillation is a direct result of earthquake faults and folds; pillow is a layer of sand caused by the earthquake fibrillation dehydration, the formation of the sinking; liquefied vein, Volcanic sand for the liquefaction of sand penetration of the formation of earthquake fissures formed; load structure, flame Construction, pillow-like structure, spherical structure is affected by the earthquake fibrillation in the sand, mudstone interface because of the sinking sand, mud layer formed through ; Slump structures and breccia of the earthquake was caused by the gravitational collapse or the formation of the debris flow. Fissures, earthquake-fold, liquefied vein, volcanic sand, load structure, flame Construction, pillow-like structure, spherical structure, pillow-like layer Equivalent to the original earthquake rocks the plot, and the slump structures and breccia of the plot belong to different earthquake rocks.

Soft-sediment deformation structures interpreted as seismite from the Middle Permian of the southern Sydney Basin, southeastern Australia

The Middle Permian Wandrawandian Siltstone of the southern Sydney Basin is well exposed along the coastline from Lagoon Head in the south to North Head in the north near Ulladulla in southern New South Wales. The unit is dominated by fossiliferous siltstone and mudstone, with abundant dropstones and minor pebbly sandstone interbeds, and contains an interval of well-preserved and extensive soft-sediment deformation structures. These deformation structures occur mainly in the middle part of the cliff sections and are bounded above and below by undeformed sedimentary units of similar lithology. A wide range of soft-sediment deformation structures have been observed, including cracks, sandstone and sandy mudstone dykes, a possible sand volcano, networks of relatively small and closely connected fissure-like structures, metre-scale complex-type slump folds, flexural stratification, concave-up depressional structures, small-scale normal faults (with displacements usually <1 m), shear planes, and breccias (pseudonodules). The slumps and associated deformations are here collectively interpreted as representing a seismite deposit attributable to penecontemporaneous deformation of soft, hydroplastic sediment layers following a liquefaction triggered by seismic shocks. The timing of the inferred earthquake events appears to correspond to the onset of a major basin-wide tectonism during the Middle Permian.

The linshuichonetes-Crurithyris community and new productid species from the Cisuralian (Early Permian) of Sichuan, China

Two marginiferinid species, Marginifera spinulifera sp. nov. and Transennatia sulcata sp. nov. are described from the Early Permian Liangshan and lowermost Chihsia formations at the Chuanmu Section, Sichuan, China. The Linshuichonetes – Crurithyris Community is discussed in the context of a pioneering opportunistic community that developed at the onset of the Yanghsingian transgression in the late Artinskian. This community was characterized by species that were generally small and relatively thin-shelled, and showed other features that are ecological adaptations to fluctuating environmental conditions.

The Permian-Triassic Boundary Stratigraphic Set: characteristics and correlation

Eased on field observations and compilation of data, a new stratigraphic concept, herein named the Permian-Triassic boundary stratigraphic set (PTBST), is proposed. The PTBST consists of, in ascending order, beds of claystone, limestone (or marl) and claystone. This boundary stratigraphic
set has been recognized at many sections in the Yangtze region of South China, with laterally stable lithological characters, the same or comparable biotas, comparable radiometric ages, and identical or similar magnetostratigraphic and chemostratigraphic signals. Therefore, the PTBST marks an isochronous unit and can serve as an important and effective marker set for regional and global correlations.
The important index fossils for the lowermost Triassic, Hindeodus parvus or Claraia, may be diachronous in their first occurrences with respect to the base of the PTBST and, therefore, should not be used as an exclusive indicator for the beginning of the Triassic. Rather more attention should
be paid to events, succession of events and/or event surfaces, which would potentially provide a more precise tool for high-resolution stratigraphic division and correlation.

End-Permian catastrophe by a bolide impact: evidence of a gigantic release of sulfur from the mantle

Our studies in southern China have revealed a remarkable sulfur and strontium isotope excursion at the end of the Permian, along with a coincident concentration of impact- metamorphosed grains and kaolinite and a significant decrease in manganese, phosphorous, calcium, and microfossils (foraminifera). These data suggest that an asteroid or a comet hit the ocean at the end of Permian time and caused a rapid and massive release of sulfur from the mantle to the ocean-atmosphere system, leading to significant oxygen consumption, acid rain, and the most severe biotic crisis in the history of life on Earth.

Middle Permian brachiopods from the Dongujimqinqi area, Inner Mongolia, China

A small collection of brachiopods is described from the lower Middle Permian Yanchibeishan Formation of the Dongujimqinqi area, eastern Inner Mongolia, China. This fauna consists of the following four species: Kochiproductus sp., Linoproductus simensis (Tschernyschew), Rhynchopora inconstantis Lee and Gu and Licharewia grewingki (Netschajew). The Dongujimqinqi fauna exhibits a strong Boreal-type aspect and suggests an early Middle Permian in age.

Permian brachiopods from the Baoshan and Simao Blocks in Western Yunnan, China

This paper describes and illustrates four Permian brachiopod assemblages (Assemblages A–D) from western Yunnan, southwest China. Assemblage A occurs in the basal part of the Yongde Formation in the Xiaoxinzhai section in the southern Baoshan Block and is assignable to the latest Artinskian or earliest Kungurian. Assemblage B occurs about 50 m stratigraphically above Assemblage A in the same section, and is of Chihsian (Kungurian–Roadian) age. Assemblage C was collected from the Yongde Formation in the Anpaitian section in the southern Baoshan Block and is most likely Roadian to Wordian in age. Assemblage D came from the Longtan Formation in the Simao Block and is of late Wuchiapingian in age. The brachiopod faunas from the Yongde Formation of the Baoshan Block, as a whole, is dominated by species characteristic of the Cathaysian Province, although some links with Peri-Gondwanan faunas are also evident. In contrast, Assemblage D from the Simao Block is characterised exclusively by taxa of the Cathaysian Province. New taxa described and illustrated are Neochonetes (Huangichonetes) inflatus n. sp. Costatumulus minor n. sp. and Celebetus yunnanensis n. sp.

Chonetoidea (Brachiopoda) from the Lopingian (Late Permian) of South China

en species of the superfamily Chonetoidea from the Lopingian (Late Permian) of South China are described or revised. A review of all recorded Chonetoidea species from the Lopingian (Late Permian) of South China indicates that some 22 species of five genera can be recognised. Species of Tethyochonetes and Neochonetes are characteristic in the lithofacies dominated by mudstone, siltstone or siliceous rocks in the Lopingian and some argillaceous limestone and clay rock facies near the Permian-Triassic boundary. New taxa are Neochoneles (Zhongyingia) subgen. nov., Neochonetes (Huangichonetes) subgen. nov. and Tethyochonetes flatus sp. nov.

Early Permian Jakutoproductus (Productida: Brachiopoda) from Patagonia, Argentina

The productid brachiopod genus Jakutoproductus, dominant in the Early Permian marine faunas of northeastern Siberia, is described for the first time from the southern hemisphere. Jakutoproductus australis sp. nov. is described from the Rio Genoa Formation, Chubut Province (Patagonia), Argentina. The age of the Patagonian species is considered to be Sakmarian (Early Permian), possibly Sterlitamakian.