ABSTRACT: The new agglutinated foraminiferal genus Rectoprotomarssonella n. gen. is characterized by its high trochospiral coiling with multiserial to uniserial chamber arrangement and solid, noncanaliculate wall with calcareous cement. This taxon shows close relationship to the Cretaceous genus Protomarssonella Desai and Banner, from which it differs in possessing a uniserial part. The type species is a stratigraphic indicator in Campanian to Maastrichtian deep-water sediments in the Western Tethys and North Atlantic.