The family position of Papposphaera Tangen and Pappomonas Manton & Oates (Prymnesiophyceae) with records from the Indian Ocean

Papposphaera and Pappomonas are coccolithophorid genera that have recently been described, but there has been little attempt to relate them to known genera and families. Analysis of coccolith structure from Indian Ocean material and the literature has revealed a relationship of these genera to a species, Defiandrius intercisus, known in fossil form from the late Cretaceous. This species and genus typify the family Deflandriaceae, defined here in the original narrow sense, and have characteristics in coccolith structure to allow Papposphaera and Pappomonas to be admitted to this family. A coccolith that may be the same as Defiandrius intercisus was discovered in the Indian Ocean extant nanoplankton flora. Two species of Papposphaera, P. sarion and P. thomsenii sp. nov., were also found in the Indian Ocean samples.