Rhabdodontomorpha is a clade of basal iguanodont dinosaurs. This group was named in 2016 in the context of the description, based on Spanish findings of an early member of the Rhabdodontidae. A cladistic analysis was conducted in which it was found that Muttaburrasaurus was the sister species of the Rhabdodontidae sensu Weishampel. Therefore, Paul-Emile Dieudonné and colleagues defined Rhabdodontomorpha as a node-based clade: the group consisting of the last common ancestor of Rhabdodon priscus and Muttaburrasaurus langdoni, and all its descendants. Within the clade Zalmoxes and Mochlodon are also included. In 2021, Daniel Madzia redefined Rhabdodontomorpha in the PhyloCode as "the largest clade containing Rhabdodon priscus, but not Iguanodon bernissartensis and Hypsilophodon foxii". The clade is characterized by the following synapomorphies:the outline of the dorsal iliac margin is sigmoidal in dorsal view, with the postacetabular process deflected medialward and the pre-acetabular process deflected laterally the dorsal iliac margin is mediolaterally broader and swollen from above the ischiac peduncle anteriorly or above the postacetabular process all along the presence of a weak, dorsally convex ridge on the ventromedial side of their postacetabular process the ischiac peduncle of the ilium is lenticular and uniquely anteroposteriorly long the acetabulum is noticeably low