Helicosphaera waltrans Theodoridis, 1984
Theodoridis, S., 1984. Calcareous nannofossil biostratigraphy of the Miocene and revision of the helicoliths and discoasters. Utrecht Micropaleontological Bulletin. 32, 1-271.
Helicosphaera waltrans
Middle Miocene
Reqqa Point, Gozo