Whittington, H. B., Stephen E. Speyer, and Brian D. E. Chatterton. “Part O, Arthropoda 1 (Revised), Vol. 1, Ch. 2, P. 137-247”. Treatise on Invertebrate Paleontology (January 1, 1997). Accessed May 6, 2024. https://journals.ku.edu/InvertebratePaleo/article/view/5612.