original descriptionUlrich, E. O.; Foerste, A. F. (1933). The earliest known cephalopods. <em>Science.</em> 78(2022): 288-289., available online athttps://doi.org/10.1126/science.78.2022.288[details] Available for editors
basis of recordEvans, D. H. (2011). The lower Ordovician cephalopod faunas of the Durness Group, North-West Scotland. <em>Monographs of the Palaeontographical Society.</em> 165(637): 1-127., available online athttps://doi.org/10.1080/25761900.2022.12131817[details]