English: Fossil material and reconstruction of Mamsetia manunis gen. et sp. nov.: (A) holotype of M. manunis preserving a thick band of coronal muscle ((com) coloured green and has no primary tentacles) and longitudinal muscles of the arms ((a) coloured orange)—note that the calyx is not coherent as it is in H. quadriformis, and the specimen was damaged by rockfall in the field, scale bar 2.5 cm; (B) large specimen of M. manunis (scale bar 5 cm), orange longitudinal muscles of the arms, scale bar 5 cm (a), and possible green coronal muscle (com)—note the branching at the tips of the arms (arrowed); (C) reconstruction of Mamsetia manunis showing the four arms and a staurozoan body plan with no primary tentacles. The exterior tissue of the calyx is made transparent to highlight the positions of the internal coronal and longitudinal musculature; (D) reconstruction of the mode of life of Mamsetia manunis.