Leptaena (Ygdrasilomena) roomusoksi was named by Cocks (2005). Its type specimen is RMS Br 102778 (conjoined valves) and is not a trace fossil. Its type locality is Osmundsberget Quarry, Boda Limestone Fm., which is in a Katian/Hirnantian reef, buildup or bioherm limestone in the Boda Limestone Formation of Sweden. It is the type species of Leptaena (Ygdrasilomena).