Liu, H. P.; Bergström, S. M.; Witzke, B. J.; Briggs, D. E. G.; McKay, R. M.; Ferretti, A. (2017). Exceptionally preserved conodont apparatuses with giant elements from the Middle Ordovician Winneshiek Konservat-Lagerstätte, Iowa, USA. Journal of Paleontology. 91(03): 493-511.