The Origin, Evolution and Taxonomy of the Foraminiferal Genus Pulleniatina Cushman, 1927

Abstract

Studies of many geographically widely separated stratigraphical sections covering the late Miocene to Recent interval have allowed the origin and evolution of species referable to the genus Pulleniatina to be traced. The evolutionary sequence Pulleniatina primalis, n. sp., P. obliquiloculata praecursor, n. subsp., P. obliquiloculata obliquiloculata and P. obliquiloculata finalis, n. subsp., is shown to be useful in biostratigraphy. Pulleniatina spectabilis is recognised as forming a separate evolutionary line from P. primalis and as having a short range in the Pliocene of the Indo-Pacific province. Pulleniatina seems to originate from Globorotalia (Turborotalia) acostaensis Blow, 1959, and the holotype of this form is re-illustrated. Globigerina inflata d9Orbigny, 1839, is shown to be unrelated to Pulleniatina obliquiloculata (s. l.), and a neotype for the former taxon is now proposed. The meaning of streptospiral coiling is examined. The new monotypic genus Rotaliatinopsis is proposed to accommodate 9?Pulleniatina semi-involuta9 Germeraad, 1946, which is unrelated to the Globigerinacea.