Early Cambrian lingulate brachiopods from the Shaanxi Province, China

A diverse fauna of lingulate (Subphylum Linguliformea, Class Lingulata) brachiopods is described from the Early Cambrian (Qiongzhusian Stage) carbonates in southern Shaanxi Province (Fucheng and Xiaoyang sections), China. Eight species assigned to 6 genera are systematically described. Among them, the taxa assigned to the Superfamily Linguloidea comprise Palaeobolus liantuoensis Zeng, Lingulellotreta malongensis (Rong), Eoobolus aff. viridis (Cobbold), Eoobolus? shaanxiensis sp. nov., and Kyrshabaktella? sp. Only Palaeobolus liantuoensis and Lingulellotreta malongensis were known previously from South China, where the latter species occurs in the soft-bodied Chengjiang fauna with preserved pedicle. The Superfamily Acrotheloidea is represented only by the new species Botsfordia minuta. The fauna also includes two primitive acrotretoid (Superfamily Acrotretoidea) species belonging to the new genus and species Eohadrotreta zhenbaensis and E. zhujiahensis; the ontogeny of Eohadrotreta supports the view that the acrotretid muscle system and ontogeny are derived in relation to the lingulide musculature and ontogeny. The fauna from Shaanxi is the oldest known diverse lingulate brachiopod assemblage from China.