North European Plain Esthonia
Geological Time: Ordovician
the image is from a publication, which is cited in the table descriptions of the below cited book by
View of a specimen of Ordovicina oligostoma Eisenack Em. Eisenack, 1954
The identification is based upon:
Loeblich, A. R., Tappan, H. N., 1987: Foraminiferal genera and their classification. Van Nostrand, Reinhold Co. New York 1728 pp. Plate 21, Fig. 3