Phenotypic evolution in a fossil gastropod species lineage: Evidence for adaptive radiation?

► Morphometric analysis of fossil gastropods is used to infer modes of evolution. ► Digitised shell outlines are processed with the Fast Fourier Transform method. ► Phenotypic shifts observed parallel palaeoenvironmental changes. ► The appearance of several new phenotypes is interpreted as adaptive radiation. ► Ongoing phenotypic divergence is considered to reflect ecological speciation.