Opinion 428 Suppression under the Plenary Powers of the specific name royerianus d'Orbigny, 1841, as published in the combination ammonites Royerianus and designation under the same Powers of a type species in harmony with accustomed practice for the genus Chehniceras, Hyatt, 1903 (class Cephalopoda, order Ammonoidea)
Published in Opinions and declarations rendered by the International Commission on Zoological Nomenclature, in 1956, in volume 14, issue 12, pages 311-322
Date published:1956-10-26