Tinglu Yang

Late Permian marine ecosystem collapse began in deeper waters: evidence from brachiopod diversity and body size changes

Analysis of Permian-Triassic brachiopod diversity and body size changes from different water depths spanning the continental shelf to basinal facies in South China provides insights into the process of environmental deterioration. Comparison of the temporal changes of brachiopod diversity between deepwater and shallow-water facies demonstrates that deepwater brachiopods disappeared earlier than shallow-water brachiopods. This indicates that high environmental stress commenced first in deepwater settings and later extended to shallow waters. This environmental stress is attributed to major volcanic eruptions, which first led to formation of a stratified ocean and a chemocline in the outer shelf and deeper water environments, causing the disappearance of deep marine benthos including brachiopods. The chemocline then rapidly migrated upward and extended to shallow waters, causing widespread mass extinction of shallow marine benthos. We predict that the spatial and temporal patterns of earlier onset of disappearance/extinction and ecological crisis in deeper water ecosystems will be recorded during other episodes of rapid global warming.

Changhsingian (latest Permian) deep-water brachiopod fauna from South China

This paper describes 45 brachiopod species (including 15 undetermined species) in 23 genera belonging to seven orders (Productida, Spiriferida, Athyridida, Orthida, Orthotetida, Rhynchonellida and Lingulida) from the Talung Formation (Changhsingian, latest Permian) of the marine deep-water facies of South China. Two new genera are proposed: Chaohochonetes and Parapygmochonetes; along with nine new species: Tethyochonetes rectangularis, Tethyochonetes? sinuata, Chaohochonetes triangusinuata, Neochonetes (Zhongyingia?) liaoi, Neochonetes (Huangichonetes?) wufengensis, Paryphella majiashanensis, Paryphella minuta, Parapygmochonetes parvulus and Meekella sparsiplicata. The taxonomic composition, significant morphological features and palaeoecological implications of this deep-water brachiopod fauna are summarized, and the fauna is compared with the Permian–Triassic boundary (PTB) mixed brachiopod fauna of South China. The Changhsingian (latest Permian) deep-water brachiopod fauna of South China shares some common features with the PTB mixed brachiopod fauna, especially in terms of taxonomic composition and certain apparent morphological adaptations. This commonality is interpreted to indicate a time and a broad marine environment of widespread low oxygen supply and/or reduced trophic resources during the end-Permian life crisis in South China. http://zoobank.org/urn:lsid:zoobank.org:pub:744771BB-7377-4239-8A29-89183ECEBE09

Systematics and palaeoecology of Changhsingian (Late Permian) Ambocoeliidae brachiopods from South China and implications for the end-Permian mass extinction

Weihong He, G.R. Shi, Yang Zhang, Tinglu Yang, Fei Teng.& Shunbao Wu, December 2012. Systematics and palaeoecology of Changhsingian (Late Permian) Ambocoeliidae brachiopods from South China and implications for the end-Permian mass extinction. Alcheringa 36, 515–530. ISSN 0311-5518. Four Ambocoeliidae brachiopod species including one new species (Crurithyris tazawai sp. nov., Crurithyris sp., Paracrurithyris pygmaea and Attenuatella mengi) are described from the Changhsingian (Late Permian) deep-water facies of South China. Analysis of the morphology, palaeoecology and palaeogeographical and temporal distributions of these species revealed that the presence of a delthyrium and/or the micro-ornaments among three of the four species (Crurithyris tazawai sp. nov., Paracrurithyris pygmaea and Attenuatella mengi) favoured an epifaunal (epiphytic) lifestyle. Morphological differences suggest that Paracrurithyris pygmaea may have been more effective metabolically in forming the shell compared with Attenuatella mengi and Crurithyris tazawai. The temporal and palaeogeographical distribution of Attenuatella suggests that A. mengi inhabited cool or cold deep waters. Both Crurithyris tazawai and Attenuatella mengi disappeared earlier in the stratigraphic record than Paracrurithyis pygmaea during the Permian–Triassic mass extinction. These differences in timing of extinction, morphology and palaeogeographical distributions suggest that oxygen deficiency and trophic resource limitation (a consequence of the changing composition of marine phytoplankton in the seas) may have contributed to the end-Permian mass extinction.

Palaeoecological insights into the Changhsingian–Induan (latest Permian–earliest Triassic) bivalve fauna at Dongpan, southern Guangxi, South China

Yang, T.L., He, W.H., Zhang, K.X., Wu, S.B., Zhang, Y., Yue, M.L., Wu, H.T. & Xiao, Y.F., November 2015. Palaeoecological insights into the Changhsingian–Induan (latest Permian–earliest Triassic) bivalve fauna at Dongpan, southern Guangxi, South China. Alcheringa 40, xxx–xxx. ISSN 0311-5518. The Talung Formation (latest Permian) and basal part of Luolou Formation (earliest Triassic) of the Dongpan section have yielded 30 bivalve species in 17 genera. Eight genera incorporating 11 species are systematically described herein, including three new species: Nuculopsis guangxiensis, Parallelodon changhsingensis and Palaeolima fangi. Two assemblages are recognized, i.e., the Hunanopecten exilis–Euchondria fusuiensis assemblage from the Talung Formation and the Claraia dieneri–Claraia griesbachi assemblage from the Luolou Formation. The former is characterized by abundant Euchondria fusuiensis, an endemic species, associated with other common genera, such as Hunanopecten, which make it unique from coeval assemblages of South China. A palaeoecological analysis indicates that the Changhsingian bivalve assemblage at Dongpan is diverse and represented by various life habits characteristic of a complex ecosystem. This also suggests that redox conditions were oxic to suboxic in deep marine environments of the southernmost Yangtze Basin during the late Changhsingian, although several episodes of anoxic perturbations and declines in palaeoproductivity saw deterioratation of local habitats and altered the taxonomic composition or population size of the bivalve fauna. Tinglu Yang [yang@geology.so], School of Earth Sciences, China University of Geosciences, 388 Lumo Road, Hongshan, Wuhan 430074, PR China; Weihong He* [whzhang@cug.edu.cn] and Kexin Zhang [kx_zhang@cug.edu.cn], State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, 388 Lumo Road, Hongshan, Wuhan 430074, PR China; Shunbao Wu [shbwu@cug.edu.cn], Yang Zhang [zhangy05@163.com], Mingliang Yue [812182779@qq.com], Huiting Wu [ht_wu415@163.com] and Yifan Xiao [shadowyi@sohu.com], School of Earth Sciences, China University of Geosciences, 388 Lumo Road, Hongshan, Wuhan 430074, PR China.

A new genus Liaous of early Anisian Stage (Middle Triassic) brachiopods from southwestern China: systematics, reassessment of classification of the Spiriferinioidea, community paleoecology, and paleoenvironmental implications

Abstract. This paper describes a new genus Liaous, with L. shaiwensis He and Chen n. gen. n. sp. as the type species, from the Xinyuan Formation of Anisian age in Ziyun, southern Guizhou, China. The phylogenetic tree revealed by the parsimony analysis shows that Liaous is closely allied to both Mentzelia Quenstedt, 1871 and Paramentzelia Xu, 1978 of the subfamily Mentzeliinae. A new classification scheme for the Spiriferinoidea is also proposed based on a phylogenetic tree of the superfamily indicated by parsimony analysis. The Spiriferinoidea includes three families and nine subfamilies. Three new subfamilies—Madoinae He and Chen, new subfam., Qinghaispiriferininae He and Chen, new subfam., and Triadispirinae He and Chen, new subfam. are proposed. Liaous shaiwensis He and Chen n. gen. n. sp. is found in the Posidonia wengensis-Liaous shaiwensis (P-L) paleocommunity, which is dominated by r-strategists (i.e., organisms defined by a fauna with a high dominance and small body sizes) and has a low diversity and high dominance. The P-L paleocommunity therefore has little similarity to its coeval communities from the Anisian Stage of South China and instead it appears more similar to the Lower Triassic shelly faunas in community structures. This paleocommunity is interpreted to have inhabited a relatively deep, low-energy, dysaerobic offshore basin/slope setting with the influence of episodic storms.

A new Permian–Triassic boundary brachiopod fauna from the Xinmin section, southwestern Guizhou, south China and its extinction patterns

Wu, H.T., He, W.H., Shi, G.R., Zhang, K.X., Yang, T.L., Zhang, Y., Xiao, Y.F., Chen, B. & Wu, S.B., XX.XXXX.2018. A new Permian–Triassic boundary brachiopod fauna from the Xinmin section, southwestern Guizhou, south China and its extinction patterns. Alcheringa 00, 000–000. ISSN 0311-5518. A new brachiopod fauna comprising 31 species in 19 genera is described from a Permian–Triassic boundary section in Xinmin, Guizhou Province, Southwestern China. The brachiopods were collected from the Changhsingian (latest Permian) Changxing (=Changhsing) and Dalong (=Talung) formations and the lower Griesbachian (earliest Triassic) Daye Formation, which were deposited, respectively, in a shallow-water carbonate platform, upper offshore and carbonate platform settings. Among the brachiopods described and illustrated, a new species Juxathyris subcircularis is proposed. In addition, some species Araxathyris previously reported in south China have been discussed in detail and revised, with new morphological information. In particular, internal structures are provided for the first time for Orthothetina and Araxathyris species reported from south China. In addition, important clarifications are also provided on the morphology and diagnoses for Haydenoides, Martinia, Crurithyris and Transcaucasathyris, as well as for Paryphella transversa. Huiting Wu School of Earth Sciences, China University of Geosciences, Wuhan 430074, PR China and School of Life and Environmental Sciences, Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood, Victoria 3125, Australia; Weihong He [whzhang@cug.edu.cn] State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan 430074, PR China; G. R. Shi [guang.shi@deakin.edu.au] School of Life and Environmental Sciences, Deakin University, Melbourne Burwood Campus, 221 Burwood Highway, Burwood, Victoria 3125, Australia; Kexin Zhang State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan 430074, PR China; Tinglu Yang Faculty of Geosciences, East China University of Technology, Nanchang 330013, PR China; Yang Zhang School of Earth Sciences and Resource, China University of Geosciences, Beijing 100083, PR China; Yifan Xiao and Bing Chen School of Earth Sciences, China University of Geosciences, Wuhan 430074, PR China; Shunbao Wu, School of Earth Sciences, China University of Geosciences, Wuhan 430074, PR China.

Morphological Evolution of Claraia Species from the Late Permian (Changhsingian) to the Early Triassic (Induan) and the Response to the Permian–Triassic Stressed Environment

Claraia ranged from the late Permian to the Early Triassic. From the early Changhsingian to the Induan, byssal notches of Claraia species became narrower, and gradually changed from being ventrally extended to being horizontally extended. As the byssal notches narrowed, many Claraia species also lost most of their radial ornamentation. This resulted in a higher ratio of Claraia species with only concentric ornamentation to Claraia species with both concentric and radial ornamentation. Claraia experienced a rapid diversification and geographical expansion from the early Changhsingian to the Early Triassic. The rapid diversification of Claraia during the Permian–Triassic transition is related to a change in the genera’s morphology, making Claraia better adapted to the stressed environment near the Permian–Triassic Boundary (PTB), and as a result leading to Claraia being a successful disaster genus.