Wuliuan followed by Drumian
The Wuliuan stage is the fifth stage of the Cambrian, and the first stage of the Miaolingian Series of the Cambrian.  It was formally defined by the International Commission on Stratigraphy in 2018.
Its base is defined by the first appearance of the trilobite species Oryctocephalus indicus; it ends with the beginning of the Drumian Stage, marked by the first appearance of the trilobite Ptychagnostus atavus around 504.5 million years ago.The 'golden spike' that formally defines the base of the period is driven into the Wuliu-Zengjiayan(乌溜-曾家崖)section of the Kaili formation, near Balang Village in the Miaoling Mountains, Guizhou, China.