Carlamuelleraceae

Carlamuelleria Varol, 2023

This transitional family between Discoasteraceae and Coccolithaceae consists of a lenticular distal shield, tube cycle and proto-proximal shield (diminutive vestigial or appressed).

The lenticular distal shield resembles rosette-shaped discoasters, but differs from them by having a tube cycle and a diminutive , vestigial, or appressed proximal shield. Carlamuelleraceae is distinguished from Coccolithaceae by having a lenticular distal shield, whereas the latter has a concave/convex shield. Moreover, Carlamuelleraceae has a proto-proximal shield (diminutive vestigial or appressed), whilst Coccolithaceae has a well-developed, concave/convex spaced proximal shield. The forms with a protruding tube cycle (i.e., Noelia kolona) superficially may look like Heliolithaceae, but differ by having a proto-proximal shield (diminutive vestigial or appressed).

Varol, O. 2023. New paleocene calcareous nannofossils: Carlamuelleria, Davidbukrya, Mauriceblackia, Noelia and Senelia. Marine Micropaleontology. 180: 1-41.