Catinaster coalitus Martini & Bramlette, 1963
The jar-shaped Catinaster develops from a Discoaster through the extreme proximal curvature of its segments until the ends of these segments converge. This transformation results in the characteristic jar-like shape of a Catinaster.
This unique morphological development is crucial in distinguishing Catinaster from its ancestors, Discoaster, and other related nannofossils. The convergence of the segment ends due to their extreme curvature, a defining feature of this genus.
Martini, E. & Bramlette, M. N. 1963. Calcareous nannoplankton from the experimental Mohole drilling. Journal of Paleontology. 37(4): 845-855.