High-quality casts of the missing holotype of Petalodus ohioensis Safford 1853 (Chondrichthyes, Petalodontidae) at the Field Museum of Natural History and their bearing on the validity and priority of the species

Abstract

The validity of the chondrichthyan species Petalodus ohioensis Safford 1853, has long been in doubt due to the poor quality of the published figures and the unknown whereabouts of the holotype. That situation changed with the discovery of casts of the holotype in the collections of the Yale Peabody Museum of Natural History. The quality of the casts is poor, but sufficient to establish P. ohioensis as a valid species and as a senior synonym of P. alleghaniensis Leidy 1856. Recently, casts of the holotype of much better quality were found in the collections of the Field Museum of Natural History, accompanied by documentation indicating that they were likely obtained directly from Safford by O.P. Hay in 1896. The Field Museum casts clearly show the bands of ridges at the base of the crown on the labial and lingual sides, which are not visible on the Yale Peabody Museum casts.