Coronocyclus serratus Hay Mohler & Wade 1966
Circular to elliptical placolith with relatively narrow pelaga and wide central opening without any structure. The tube cycle bears spines. The proximal shield is made up of strongly imbricated chevron-like segments. Entirely fully birefringent in polarised light.
Coronocyclus differs from Pedinocyclus and Umbilicosphaera by its serrate outlook created with the spines of the tube cycle. The species of Coronocyclus are identified based on their overall size and shape and the width of their pelaga.
Hay, W. W., Mohler, H. P. & Wade, M. E., (1966): Calcareous nannofossils from Nal'chik (northwest Caucasus). - Eclogae Geologicae Helvetiae. 59: 379-399.