Geometric morphometrics species discrimination within the genus Terebratula from the Late Cenozoic of Italy

The genus Terebratula has a long and complex nomenclature history that has resulted in much confusion over species validity, description and definition. Although partially remedied by Lee and her colleagues in 2001, there are still major concerns regarding the validity of some often-cited species whose formal description is still deficient and whose distinctiveness has never been tested. In this paper we analyze (statistically) the shape variability of Terebratula terebratula, Terebratula scillae, Terebratula ampulla and the controversial Terebratula 'sintiosa', with the aid of geometric morphometrics. Although now considered a synonym of T. terebratula, we found T. 'sinuosa' to be a separate morphotype, mostly following Brocchi's original description in 1814. We found strong support for significant morphological distinction of the species we analyzed and anticipate further studies to revise the validity of those species. Morphometric analysis, multivariate statistics, shape variation, Terebratula.