Intra- and interspecific variation in internal structures of the genus Stenosarina (Brachiopoda, Terebratulida) using landmarks

Although a number of brachiopod genera have been defined mainly from their internal structures, the fixity of those structures has rarely been investi gated. Variability of the rather simple loops of two New Caledonian species of the Recent genus Stenosarina (Terebratulida), one species having a vari ant with endemic morphology, provides insight into the relationship between the two species. Procrustes methods based on landmarks are used. Intra-pop ulation variability is found to be of the same order of magnitude as inter- population variability. Moreover, the morphological distance between the en demic variant and the other specimens is greater than the distance between the two species of Stenosarina. The study also identifies a morphocline bet ween the three forms of Stenosarina under study.