Revisiting the hadrosaurid (dinosauria: ornithopoda) diversity of the Allen Formation: a re-evaluation of Willinakaqe salitralensis from salitral Moreno, Río Negro province, Argentina.

Abstract

The alpha taxonomic diversity of hadrosaurids in South America is modest compared with that of North America. Currently, it consists of three species: Secernosaurus koerneri Brett-Surman, 1979; Prieto-Márquez, 2010), Willinakaqe salitranensis Juárez Valieri, Haro, Fiorelli, Calvo, 2010 and Lapampasaurus cholinoi Coria, González Riga, Casadío, 2012. This diversity has been a matter of debate in later years (Prieto-Márquez and Salinas, 2010; Coria, 2014). One of the most productive stratigraphical units with hadrosaurid bones is the late Campanian Allen Formation, widely exposed in northern Patagonia. The hadrosaurid Willinakaqe salitralensis (Juárez Valieri et al., 2010) was described to include all hadrosaurid remains from that unit, based on information gathered from both associated and isolated specimens. Coria et al. (2012) later identified as a different taxon a specimen collected from the Allen Fm. in La Pampa Province and originally referred to Willinakaqe, i.e., Lapampasaurus cholinoi. In a recent review of the South American hadrosaurid diversity, Coria (2014) casted some doubts on the taxonomic assignment of most of the material referred to W. salitralensis. He defined the holotype specimen (an incomplete<br />premaxilla) as the only material representing that taxon. Here we analyze in detail the remains assigned to W. salitralensis and discuss the taxonomic status of this form.