Brachiopods from the Latham Shale Lagerstätte (Cambrian Series 2, Stage 4) and Cadiz Formation (Miaolingian, Wuliuan), California

Abstract A moderately diverse assemblage of brachiopods from the Latham Shale Lagerstätte (Cambrian Series 2, upper Stage 4) and Cadiz Formation (Miaolingian, Wuliuan), California is described in detail for first time. The fauna includes both linguliform rhynchonelliform brachiopods— Hadrotreta primaea (Walcott, 1902), Paterina prospectensis 1884), Dictyonina pannula (White, 1874), Mickwitzia occidens Walcott, 1908; Nisusia fulleri Mount, 1981 Wimanella highlandensis 1886), respectively—together with olenellid trilobites hyolithids. differs other Cambrian Konservat-Lagerstätten (notably 2 Chengjiang Guanshan Lagerstätten, eastern Yunnan) that brachiopod shell valves many cases are still preserved their original mineralization. Moreover, excellently shale-hosted even include exquisite epithelial cell molds, otherwise only seen acid-etched material carbonate rocks. pitted ornamentation D. closely resembles Ordovician linguliforms. unusual preservation N. provides important clues ancestral composition shell. two articulated species probably represent oldest records this group west Laurentia. could also earliest onset transition Evolutionary Fauna (CEF) to Paleozoic (PEF).