The paper discusses the role and significance of biostratigraphy in deciphering the structures, facies models and dating event stratigraphic surfaces of the intricately deformed Paleogene sediments comprising the Subathu, Dagshai and Kasauli formations (Late Thanetian-Early Miocene) of the Surajpur Tectonic Unit of the Himalayan Foreland Basin. The larger foraminifera, particularly the Nummulitdae, which occur in great abundance in distinct foraminiferal bands in the Subathu Formation are chronologically significant and facilitate recognition of Shallow Benthic Faunal Zones throughout the Tethyan Zone, including the Himalayan Foreland Basin.