There are no syntype specimens known. Warren et al. (1994) examined specimens said to be "Rasmussen's private collection from type locality" and give a "type locality" of Vellerup Vig, Isefjord, 55°44'N 11 °52'E (55.733, 11.8667), 0.5 m. How they obtained the lat/long is unstated, but it is a location inside Vellerup Vig.