A singular echinoid (Echinoidea: Cassiduloida) from the Barremian of Ares del Maestrat

Un equínid singular d’Ares del Maestrat (l’Alt Maestrat) es descriu i figura. Es discuteix la seua posiciótaxonòmica. Es deixa l’espècie amb nomenclatura oberta i s’assigna, amb dubtes, al gènere AcriasterSmith, 1991. S’indica la conveniència de revisar la diagnosi de la família Archiaciidae Cotteau & Triger,1869A singular echinoid (Echinoidea: Cassiduloida) from the Barremian of Ares del Maestrat A singular echinoid from Ares del Maestrat (l’Alt Maestrat, northeastern Spain) is described andfigured. After discussing its taxonomic position, the species has been left with an open nomenclatureand assigned, with some doubts, to Acriaster Smith, 1991. The convenience of revising the diagnosticcharacters of the family Archiaciidae Cotteau, & Triger, 1869 is also indicated.A singular echinoid from Ares del Maestrat (l'Alt Maestrat, northeastem Spain) is described and figured. After discussing its taxonomic position, the species has been left with an open nomenclature and assigned, with some doubts, to Acriaster Smith, 1991. The convenience of revising the diagnostic characters of the family Archiaciidae Cotteau, & Triger, 1869 is also indicated