The rudist species Toucasia carinata (MATHERON, 1842), Pseudotoucasia santanderensis (DOUVILLÉ, 1889), P. catalaunica ASTRE, 1932 (Requieniidae), Horiopleura baylei (COQUAND, 1865), Polyconites verneuili (BAYLE, in de Verneuil et al. 1860) ("Caprotinidae"), and Caprina parvula (DOUVILLÉ & O'GORMAN, 1933) (Caprinidae) from the Aptian of NE Spain are described. Taxonomical important sections are illustrated and taxonomical problems are discussed. The study reveals that we still know very little about the ontogenetic character variation within closely related species and genera. This can hamper straightforward determinations and phylogenetic interpretations. Implicitly, it can also curtail the value of these taxa for biostratigraphical and palaeobiogeographical purposes, improvements in these fields will be largely connected to intensified basic taxonomic work, that is, to the study and illustration of morphological variations within these groups.
- Character variation
- NE Spain