Ostracods (Crustacea) through the Permian-Triassic boundary in South China: the Meishan stratotype (Zhejiang Province)

摘要

The Global Stratotype Section and Point (GSSP) of the Permian-Triassic boundary, located in Meishan, Zhejiang Province, South China, was sampled bed-by-bed for ostracods. Ninety-eight species belonging to forty-three genera are recognized. Twenty-five new species are described and figured: Bairdia bassoni Crasquin sp. nov., B. broutini Crasquin sp. nov., B. deweveri Crasquin sp. nov., B. fangnianqiaoi Crasquin sp. nov., B. gaelleae Crasquin sp. nov., B. limatusformis Forel sp. nov., B. paussi Crasquin sp. nov., B. pierrevalentini Crasquin sp. nov., B. wushunbaoi Crasquin sp. nov., Baschkirina ballei Crasquin sp. nov., B. huzhouensis Forel sp. nov., Basslerella annesophieae Crasquin sp. nov., Hollinella martensiformis Crasquin sp. nov., Kempfina taihuensis Forel sp. nov., Knightina hongfui Crasquin sp. nov., Liuzhinia praeantalyaensis Forel sp. nov., Microcheilinella rectodorsata Forel sp. nov., M. shicheni Crasquin sp. nov., M.? multinodosa Forel sp. nov., Orthobairdia lemairei Crasquin sp. nov., Paraparchites chenshii Crasquin sp. nov., Praezabythocypris?pulchraformis Forel sp. nov., Samarella meishanella Forel sp. nov., S. victori Crasquin sp. nov., and Silenitesi zhejiangensis Forel sp. nov. One new genus name is proposed: Kempfina Crasquin nom. nov. The stratigraphic distribution of all the species is given. Ostracod biodiversity variations are analyzed through the section. The main drop is recorded in bed 22, occurring a little earlier in ostracods than in foraminifers, corals and brachiopods. The decline in ostracod diversity is more progressive than in the other groups. Variations in ostracod biodiversity during the Changhsingian are related to fluctuations in palaeoenvironmental conditions.