What is "planorbulinacea"

Planorbulinacea is a superfamily of rotalliid Foraminifera that has been extant since the Early Cretaceous ( Berriasian), characterized by trochospiral tests, at least in early stage but which later may become uncoiled. The test wall is of perforate hyaline calcite, commonly optically radial in structure, with crystallographic c-axes perpendicular to the surface. The apertural face may be imperforate; the aperture interiomarginal and extraumbilical-umbilical to nearly equatorial in coiled forms, subterminal in uncoiled forms.

The Planorbulinacea unites six families which are distinguished primarily by their morphological differences.