[3] The last two zones of the Middle Cambrian are the Bathyuriscus–Elrathina-zone (contemporaneous with the Burgess Shale) and the subsequent Bolaspidella-zone (starting at the base of the Drumian stage[4]).
In case of the youngest zone, this is Eokochaspis nodosa, that also marks the base of the Wuliuan.
Species: Bolbolenellus euryparia (lower half), Mesonacis fremonti, Bristolia fragilis s.l.
Species: Peachella iddingsi (lower half), Mesonacis fremonti, Olenellus nevadensis (lower part), Bristolia anteros (lowest half), Bristolia fragilis s.l., Olenellus terminatus s.l., Paranephrolenellus besti (very short period in the late lower part), Peachella brevispina (middle part).
(upper half), Paranephrolenellus inflatus (very short interval in the middle), Eopeachella angustispina (uppermost part).