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Miaolingian First Appearances
The Miaolingian is the third Series of the Cambrian Period, and was formally named in 2018. It lasted from about to million years ago and is divided in ascending order into 3 stages: the Wuliuan, Drumian, and Guzhangian. The Miaolingian is preceded by the unnamed Cambrian Series 2 and succeeded by the Furongian series. Definition A number of proposals for fossils and type sections were made before it was formally ratified in 2018. The most promising fossil markers were seen to be the respective first appearances of either trilobite species ''Ovatoryctocara granulata'' or ''Oryctocephalus indicus'', which both have an age close to million years ago. After some deliberation, the FAD of ''Oryctocephalus indicus'' was chosen to be the lower boundary marker, and the GSSP was placed in Wuliu-Zengjiayan, Guizhou, China. The Miaolingian-Furongian boundary has the same definition as the Paibian Stage. It is defined as the first appearance of ''Glyptagnostus reticulatus'' around mill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Commission On Stratigraphy
The International Commission on Stratigraphy (ICS), sometimes referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphical, geological, and geochronological matters on a global scale. It is the largest subordinate body of the International Union of Geological Sciences (IUGS). The ICS is essentially a permanent working subcommittee, which meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress or membership of the whole. Aims One of its main aims, a project begun in 1974, is to establish a multidisciplinary standard and global geologic time scale that will ease paleontological and geobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype Section and Points (GSSPs) within the fossil record. (i.e. section of the rock rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |