Smaller size is generally seen as a negative response of organisms to stressful environmental
conditions, associated with low diversity and species dominance. The mean size of the
coccolithophorids decreased through the Neogene, leading to the prediction that their extant
representatives are characterized by poor diversification and low specialization. The study of the
(exo)coccospheres of selected taxa in the order Syracosphaerales negates this prediction,
revealing that on the contrary some extant lineages are highly diversified and remarkably
specialized. Whereas the general role of coccoliths remains indeterminate, this analysis suggests
that some highly derived coccoliths may be modified for the collection of food particles,
including picoplankton, thus implying that mixotrophy may characterize these lineages. In the
extant coccolithophorids, species richness of genera is inversely correlated with the size of cells,
definitive evidence that small size is part of a morphologic strategy rather than a sign of
evolutionary failure. Because of their extreme minuteness, the extant nannoplankton can be well
compared to Lilliputians, but the trend toward size decrease in Neogene lineages is not
attributable to the Lilliput effect described by Urbanek (1993).
