Phanulithus anfractus Jakubowski, 1986
From the Greek asaphes, dim, referring to its dark segments under cross-polarised light
Elliptical holococcoliths composed of four segments exhibiting whitish-grey interference colours, lacking a distal process, and surrounded by a wall with white interference colours.
This holococcolith exhibits segments separated by distinct sutures that vary in shape and orientation. Pores may occur along the suture lines. The sutures intersect at or near the centre, without forming a distal process. The rim typically displays white interference colours.
Asapholithos is distinguished from other holococcolith genera by its four segments, which exhibit whitish-grey interference colours, and by the absence of a distal process. Calculites also has four segments, but its segments display white to yellowish interference colours and are characterised by the presence of a distal process.
Jakubowski, M., 1986. New calcareous nannofossil taxa from the Lower Cretaceous of the North Sea. INA Newsletter. 8, 38-42.
Sissingh, W. 1977. Biostratigraphy of Cretaceous calcareous nannoplankton. Geologie en Mijnbouw. 65(1): 37-65.