ABSTRACT:Taxonomy of fossil coccolithophores is based primarily on the heterococcolith life cycle stagemorphology and, at species level, on fine variations in size and shape. Coccolith size is relevant on routine identification of certain calcareous nannofossil species, but morphometry can also be a tool to study their morphological plasticity. Here we used a new morphometric statistical method to reassess Coccolithus pelagicus s. l. data from the Holocene of the west coast of Iberia. Our results suggest that both C. pelagicus subsp. braarudii and C. pelagicus subsp. pelagicus present morphological plasticity in response to (paleo)environmental changes, mainly variations in the upwelling regime in the west coast of Portugal and (paleo)oceanographic conditions in the North Atlantic linked to glacial periods of the Holocene.