Moore RC, Strimple HL, Fay RO, Lane NG, Sprinkle J. Part T, Echinodermata 2, vol. 1-3, ch. 5, p. 520 - 630. InvertebratePaleo [Internet]. 1978 Jan. 1 [cited 2024 Jul. 22];. Available from: https://journals.ku.edu/InvertebratePaleo/article/view/5646