A Proposal for Taxonomic Re-Evaluation of Vaccinites Species from the Santonian Limestones of Southern Istria (Croatia)

Abstract

Rudists, especially members of the family Hippuritidae, were commondwellers on the Adriatic Carbonate Platform during the LateCretaceous. Morphological elements (ligamental ridge, teeth, pillars,length of the contour around the inner margin of the outer shell layerand the ratio between this length and the distance between the suturesof the pillars) from the transverse shell sections permit different speciesto be defined within the family. Transverse sections of Vaccinitesspecimens from the Santonian limestones in southern Istria show differentvalues of the angle between the teeth and the ligament ridge,between the ligamental ridge and the E pillar (P2), and of the ratiobetween the length of the contour and the pillar suture distance. Clusteranalyses (Ward’s and Unweighted pair–group average methods)using measured elements, allowed the definition of three speciesgroups from seventeen species at the beginning of study.