Revisió de Trapezium nucleus (Coquand, 1865) (Mollusca, Bivalvia) de l’Aptià de la conca del Maestrat

Abstract

Revision of Trapezium nucleus (Coquand, 1865) (Mollusca, Bivalvia) from the Aptian of the Maestrat basin
The description of Trapezium nucleus (Coquand, 1865) is completed and a diagnosis is given. A biometric study of population of Maestrat basin and differences between Oliete sub-basin and Morella sub-basin are done. An ontogenetic analysis is made and a neotype is designated. T. nucleus is compared with Tapes parallela Coquand, 1865 holotype. T. nucleus and T. parallela are now considered as separated species, although immature forms are very similar. The distribution of T. nucleus is extended in two new localities both belonging to the Morella sub-basin: el Forcall and Vallibona (els Ports, Castelló).