Zygodiscus sigmoides Bramlette & Sullivan, 1961
From Latin, derivantur portantes, stem bearing- referring to its distal process
Loxolith has an uneven inner wall height (the inner wall is higher around the short axis but much lower at the ellipse's long axis). The central area is spaned by a traverse bar or an axial cross with a distal process.
Bramlette, M. N., Sullivan, F. R., 1961, Coccolithophorids and related nannoplankton of the Early Tertiary in California. Micropaleontology 7(2), 129-188.