Vacchi’s palatal organ: a widespread trait in Holocephali

A palatal organ, possibly used for food sorting and processing, has previously been identied amongthe vomerine toothplates of the chimaeroid Chimaera monstrosa. In this study, the palatal organ wasdescribed in six additional species, conrming it is a widespread trait among holocephalans. It is pro-posed that this palatal structure, which appears to differ in shape according to each chimaeroid’s degreeof durophagy and is not homologous to the palatal structure described in teleosts, be hereby referredto as Vacchi’s organ