Rhabdodontidae is a family of herbivorous iguanodontian ornithopod dinosaurs whose earliest stem members appeared in the middle of the Lower Cretaceous.

[1] The following cladogram was recovered by Dieudonné and colleagues in 2016:[1] Anabisetia Tenontosaurus Dryomorpha Muttaburrasaurus Vegagete Ornithopod Mochlodon Rhabdodon Zalmoxes Rhabdodontids first appeared during the Barremian stage of the Early Cretaceous, and an extensive fossil record shows that they remained extant until the Maastrichtian stage at the end of the Late Cretaceous.

During much of the Late Cretaceous, an isolated island habit in the western Tethyan archipelago contributed to the evolution of rhabdodontids in two main ways.

First, the rhabdodontid dentition is relatively primitive, which is consistent with their habitat being sheltered from expansive mixing leading to a long period of dominance.

[6] Second, the fossil record contains three genera of rhabdodontids – Mochlodon, Zalmoxes, and Rhabdodon – that make up two geographically separated lines in the archipelago.

However, Ősi et al. (2012) proposed that Rhabdodon underwent gigantism on the mainland, as opposed to Zalmoxes and Mochlodon experiencing nanism on island habitats.

The conclusion was that in the eastern lineage comprising Zalmoxes and Mochlodon, the size ranges of both were too close to that of the ancestral rhabdodontid to support the hypothesis of nanism.