FELL, H. B.; REGNÉLL, Gerhard; KESLING, R. V.; MOORE, R. C.; UBAGHS, Georges. Part U, Echinodermata 3, vol. 1 & 2, ch. 2, p. 108-210. Treatise on Invertebrate Paleontology, [S. l.], 1966. DOI: 10.17161/dt.v0i0.5654. Disponível em: https://journals.ku.edu/InvertebratePaleo/article/view/5654.. Acesso em: 6 may. 2024.