Reanalysis of the phylogenetic status of Nipponosaurus sachalinensis (Ornithopoda: Dinosauria) from the Late Cretaceous of Southern Sakhalin

Nipponosaurus sachalinensis is the only definitive lambeosaurine hadrosaurid from Sakhalin Island of Russia. Previous studies suggested it was a member of Lambeosaurini (derived lambeosaurines). However, its phylogenetic status within Lambeosaurini remains controversial. In addition, some studies argued the juvenile ontogenetic stage of the holotype and regarded Nipponosaurus as an invalid taxon. In order to solve these problems, its definite...