A fresh look at Nisusia Walcott, 1905 from the Cambrian Kaili Formation in Guizhou

Nisusia Walcott, 1905 is an early genus of kutorginid brachiopod of the Subphylum Rhynchonelliformea. Originating in the Cambrian Series 2 and becoming extinct in the late Cambrian Series 3, Nisusia existed for a relatively short period of geologic time, and is a brachiopod genus that exhibited a slow rate of morphological evolution. This paper details the brachiopod Nisusia from the middle Cambrian Kaili Konservat-Lagerstätte. Nisusia, in terms of abundance, is one of the most important brachiopods from the Kaili Biota. Two Nisusia species from the Kaili Formation of the Cambrian Series 2-3 in the eastern part of Guizhou Province are described, Nisusia granosa and Nisusia guizhouensis n. sp. This study will give valuable insights into the morphological variability of Nisusia species, and provides new details on the composition of the brachiopod community in the Kaili Biota.