Species within the Eunotia praerupta - Eunotia bidens group also possess slight dorsal undulations and should be compared with E. richbuttensis. The two dorsal undulations of E. richbuttensis distinguish it from the rounded dorsal margin of E. inflata. Eunotia superbidens valves have dorsally recurved ends, in comparsion to the round, or flat ends, that are not recurved toward the dorsal margin in E. richbuttensis. Eunotia richbuttensis valves are more narrow and consistently possess one apical rimoportula, in contrast with the wider valves of E. bidens, where rimportulae are lacking.