Xianguangia Chen & Erdtmann, 1991

Zhao, Yang, Hou, Xian-guang & Cong, Pei-yun, 2023, Tentacular nature of the ‘ column’ of the Cambrian diploblastic Xianguangia sinica, Journal of Systematic Palaeontology (2215787) 21 (1), pp. 1-15 : 3

Genus Xianguangia Chen & Erdtmann, 1991

Type species. Xianguangia sinica Chen & Erdtmann, 1991

Diagnosis. As for the type and only species.

Remarks. The different architecture of the calyx separates Xianguangia from Daihua and Dinomischus ( Table 1 ). Xianguangia only possesses an invaginated pit in the basal portion of the calyx, whereas the latter two taxa have either a blunt tip or a slender stalk, respectively ( Zhao et al., 2019). The oral surface expands to various degrees among these three taxa, forming three oral domes with slender bracts in Daihua , and an elongated oral cone in Dinomischus ( Zhao et al., 2019) . Xianguangia shares with Daihua and Dinomischus an outer sheath enveloping each tentacle rod. A single sheath has been identified in Xianguangia and Dinomischus , while two possible paired sheaths have been suggested in Daihua ( Zhao et al., 2019) .