Broinsonia staytonae

Broinsonia staytonae Bukry, 1969

Helicolithus blairiae Kita, Bergen & Watkins, 2016

Species of Broinsonia having a birefringent axial cross, strongly birefringent narrow fluted tube cycle, and a dim, narrow distal shield. The axial cross's shorter arm is parallel-sided and slightly oblique, whilst the longer arm is lozenge shape and strongly dislocated along the short axis. Both arms have two halves. The central mesh is only visible in exceptionally well-preserved specimens. Due to the narrow widths of the tube cycle and distal shields artificially appears like loxolith.

Bukry, D., (1969): Upper Cretaceous coccoliths from Texas and Europe. - The University of Kansas Paleontological Contributions, Article 51 (Protista 2): 1-79.

Kita, Z.A., Watkins, D.K. & Bergen, J.A., (2016): A new calcareous nannofossil species of the genus Helicolithus from the Santonian and its biostratigraphic significance in the Cretaceous Western Interior Seaway. - Journal of NannoplanktonResearch, 36(1): 77-82.