Nummulites solitarius - Nummulites burdigalensis lineage in Kutch with remarks on the age of Naredi Formation

Three successive subspecies of evolved from . These include and . The evolving lineage is traced in a borehole drilled through the Naredi Formation of Kutch. The associated taxa include and in the lower part and and in the upper part of the formation. The better stratigraphic resolution achieved by subspecies identification and the lately redefined Ilerdien Stage in the background of Early Eocene carbon isotope excursion marker, lead to constrain the age of Naredi Formation as Early Eocene, ranging from shallow-benthic zones SBZ6 to SBZ11.