A small planispiral rotaliid, Nonion? niveum, was described by Lafrenz from the Eemian (upper Pleistocene) of the Baltic Sea. Since then, the species has several times been attributed to other genera (Haynesina, Protelphidium), resulting in taxonomic confusion. Recently, a morphologically identical foraminifer has been found in the White Sea, which is the first documented occurrence of the species from this area. In-depth investigation of its test morphology revealed that the species has features common to modern Haynesina representatives and particularly to the extinct Paleogene species Protelphidium hofkeri. This was especially evident in the architecture of the umbilical area. With the help of a comparative morphological study of several other elphidiids, the species in question was attributed to the genus Protelphidium, as its only living member and with the necessary emendation of the diagnosis. We believe that the redescription of Protelphidium niveum helps to clarify the taxonomy of the basal “lower” elphidiids by coupling the revision of morphological features with molecular data.
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