UBAGHS, Georges; DURHAM, J. Wyatt; CASTER, K. E. Part S, Echinodermata 1, vol. 1 & 2 ,Ch. 5, p. 565 - 637. Treatise on Invertebrate Paleontology, [S. l.], 1968. DOI: 10.17161/dt.v0i0.5638. Disponível em: https://journals.ku.edu/InvertebratePaleo/article/view/5638. Acesso em: 13 apr. 2025.