The Assemblage Characteristics And Evolutionary Status Of Jianhe Biota

Discovered in Balang Village,Jianhe County,Guizhou Province in 2008.The Jianhe Biota was officially named by Yuanlong Zhao at the Guanling Academic Conference of the Chinese Annual Palaeontological Conference in 2011.the research team led by Yuanlong Zhao began carrying out systematic research on fossil categories of Jianhe Biota from 2010 and completed basic research work on its fossil categories in 2019.In 2020,the author conducted research on the assemblage characteristics and evolutionary status of the Jianhe Biota.The Jianhe Biota was preserved in the stratum dominated by limestone and dolomite,which distributed across the intervals 160m-240 m in “Tsinghsutung Formation” in Songshan section,Balang Village,Jianhe County,Guizhou Province.The Jianhe Biota is composed of ten biological phyla including arthropods,brachiopods,molluscs,sponges,cnidarians,echinoderms,priapulidas and algae,and it contains 52 genera and 62 species in total,among which 47 genera of animal fossils are included and arthropods takes the largest proportion,up to 24 genera and 30 species,accounting for 46.15% of the Jianhe Biota.In addition,the Jianhe Biota bears similar assemblage characteristics to most Burgess Shale-type biotas,with arthropods dominated,And it’s worth noting that the Jianhe Biota contains a few fossils of Vetulicola,which features the Burgess Shale-type biota in Guizhou.The Jianhe Biota is present in the upper part of the Protoryctocephalus arcticus Zone of the “Tsinghsutung Formation”(located in the upper position of the Cambrian Series 2 and Stage 4),between the Balang Fauna and the Kaili Biota,and its age is slightly earlier than that of Shilongdong Biota.The discovery of the Jianhe Biota,Qingjiang Biota and Fulu Biota shows that the distribution of early metazoic biota is widespread without regard to the environmental differences and extensive fossil preservation,which optimizes the Cambrian fossils record incompleteness.The discovery of Jianhe Biota provides not only important materials for the study of the Cambrian Burgess Shale-type biota,bringing closer the evolutionary linkage among biotas(Chengjiang Biota-Kaili Biota-Canada Burgess Shale Biota),but also biological evolutionary information for the study of global Cambrian.