Macurda, Jr. DB, Roux M, Strimple HL, Brower JC, Ubaughs G, Lane NG, et al. Part T, Echinodermata 2, vol. 1-3, ch. 2, p. 217 - 316. InvertebratePaleo [Internet]. 1978 Jan. 1 [cited 2024 May 2];. Available from: https://journals.ku.edu/InvertebratePaleo/article/view/5643