The lost fossil of the first discovered rebbachisaurid: reassessment of Nopcsaspondylus alarconensis (Diplodocoidea, Sauropoda)

Abstract

Rebbachisauridae is a group of diplodocoid sauropods mainly record from the Hauterivian toTuronian of Europe, Africa and South America. They were specifically abundant for theCenomanian-Turonian times of Patagonia, Argentina. At now, at least six species have beenrecovered from the Huincul Formation, out of the 22 species currently known. However, thefragmentary nature of the bones and the isolated remains may generate an overestimated numberof species. Nopcsaspondylus is known by a middle to posterior dorsal vertebra which is currentlylost. The reassessment of Nopcsaspondylus does not find any diagnostic character which allows torecognise as a distinct species of rebbachisaurid. In addition, the erection of Nopcsaspondylus didnot follow certain recommendations of the International Code of Zoological Nomenclature (ICZN),allowing to determinate that Nopcsaspondylus represents a nomen dubium.