After the end-Permian mass extinction, genus Claraia （Bivalvia） was the most abundant and most noticeable fossil during the survival and recovery stage. However, the reasons for the proliferation of Claraia are stil...After the end-Permian mass extinction, genus Claraia （Bivalvia） was the most abundant and most noticeable fossil during the survival and recovery stage. However, the reasons for the proliferation of Claraia are still debated. This paper describes a new Griesbachian （Early Triassic） mollusc fauna from deep-water settings in South China in the aftermath of end-Permian mass extinction. This fauna yielded five bivalve species in two genera （Claraia griesbachi, C. wangi, C. stachei, C. radialis, and Promyalina putiatinensis） and two ammonoid species （Ophiceras sp. and Ussuridiscus sp.） and could be assigned to the Claraia wangi-C, griesbachi assemblage zone, indicating a Middle-Late Griesbachian Age. The bivalves were dominated by Claraia griesbachi and were featured by articulated Claraia fossils. As Claraia was epibyssate, it was an excellent autochthonous fauna. While the shallow and deep marine water became dysoxic to anoxic globally, as indicated by recent studies of the early Early Triassic, we suggest the genus Claraia could tolerate dysoxic and/or anoxic conditions and its proliferation could be attributed to its physiological features which were adapted to the stressed environment. The wide distribution of Claraia was probably related to its planktonic larval stage. Where the larva of Claraia could have been transported by ocean flow and increased its potential for long-distance dispersal. In addition, Claraia was a significant disaster and opportunistic taxon during the Early Triassic based on observations in South China.展开更多
There are different opinions on whether Claraia appeared in the Late Permian or not. Itis convinced that Claraia had turned up in the Late Permian through the study on the Upper Per-mian in South China. Pseudoclaraia,...There are different opinions on whether Claraia appeared in the Late Permian or not. Itis convinced that Claraia had turned up in the Late Permian through the study on the Upper Per-mian in South China. Pseudoclaraia, Claraioides and Claraia are compared and they are found tobear basically the same features. According to the rule of nomenclatural priority, Pseudoclaraiaand Claraioides should be attributed to the genus Claraia. Late Permian Claraia lived in the mid-dle-lower part of the bathyal continental slope as epifauna, which could swim occasionally. Thestudy on Claraia of the Permian-Triassic transition shows that Triassic Claraia was evolved fromPermian展开更多
基金supported by the National Natural Science Foundation of China (No. 41502012)the Yangtze Youth Fund of Yangtze University China (No. 2015cqn27)
文摘After the end-Permian mass extinction, genus Claraia （Bivalvia） was the most abundant and most noticeable fossil during the survival and recovery stage. However, the reasons for the proliferation of Claraia are still debated. This paper describes a new Griesbachian （Early Triassic） mollusc fauna from deep-water settings in South China in the aftermath of end-Permian mass extinction. This fauna yielded five bivalve species in two genera （Claraia griesbachi, C. wangi, C. stachei, C. radialis, and Promyalina putiatinensis） and two ammonoid species （Ophiceras sp. and Ussuridiscus sp.） and could be assigned to the Claraia wangi-C, griesbachi assemblage zone, indicating a Middle-Late Griesbachian Age. The bivalves were dominated by Claraia griesbachi and were featured by articulated Claraia fossils. As Claraia was epibyssate, it was an excellent autochthonous fauna. While the shallow and deep marine water became dysoxic to anoxic globally, as indicated by recent studies of the early Early Triassic, we suggest the genus Claraia could tolerate dysoxic and/or anoxic conditions and its proliferation could be attributed to its physiological features which were adapted to the stressed environment. The wide distribution of Claraia was probably related to its planktonic larval stage. Where the larva of Claraia could have been transported by ocean flow and increased its potential for long-distance dispersal. In addition, Claraia was a significant disaster and opportunistic taxon during the Early Triassic based on observations in South China.
基金the National Natural Science Foundation of China (Grant No. 49632070).
文摘There are different opinions on whether Claraia appeared in the Late Permian or not. Itis convinced that Claraia had turned up in the Late Permian through the study on the Upper Per-mian in South China. Pseudoclaraia, Claraioides and Claraia are compared and they are found tobear basically the same features. According to the rule of nomenclatural priority, Pseudoclaraiaand Claraioides should be attributed to the genus Claraia. Late Permian Claraia lived in the mid-dle-lower part of the bathyal continental slope as epifauna, which could swim occasionally. Thestudy on Claraia of the Permian-Triassic transition shows that Triassic Claraia was evolved fromPermian
