Rhabdodontids were herbivorous ornithopod

Ornithopod

Ornithopods or members of the clade Ornithopoda are a group of ornithischian dinosaurs that started out as small, bipedal running grazers, and grew in size and numbers until they became one of the most successful groups of herbivores in the Cretaceous world, and dominated the North American...

 dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s from the Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 Period. Rhabdodontids were similar to large, robust hypsilophodont

Hypsilophodont

Hypsilophodonts were small ornithopod dinosaurs, regarded as fast, herbivorous bipeds on the order of 1–2 meters long . They are known from Asia, Australia, Europe, New Zealand, North America, and South America, from rocks of Middle Jurassic to late Cretaceous age...

s, with deep skulls and jaws. The family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 was first proposed by David B. Weishampel et al. in 2002. The rhabdodontids were defined as "the most recent common ancestor of Zalmoxes

Zalmoxes

Zalmoxes is a genus of herbivorous dinosaur from the Late Cretaceous of what is now Romania. It is classified as a rhabdodontid iguanodont....

 robustus and Rhabdodon

Rhabdodon

Rhabdodon is a genus of dinosaur that lived in Europe approximately 70 million years ago in the Late Cretaceous. It is unclear whether it was an iguanodont or a hypsilophodont, and may be a "missing link" between the two. Current evidence indicates it is an iguanodont similar to Tenontosaurus...

 priscus and all the descendants of this common ancestor". In 2005, Paul Sereno

Paul Sereno

Paul Callistus Sereno is an American paleontologist from the University of Chicago who discovered several new dinosaur species on several continents. He has conducted excavations at sites as varied as Inner Mongolia, Argentina, Morocco, and Niger...

 defined the family as "the most inclusive clade

Clade

A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

 containing Rhabdodon priscus but not Parasaurolophus

Parasaurolophus

Parasaurolophus is a genus of ornithopod dinosaur that lived in what is now North America during the Late Cretaceous Period, about 76.5–73 million years ago. It was an herbivore that walked both as a biped and a quadruped. Three species are recognized: P. walkeri , P. tubicen, and the...

 walkeri". The Rhabdodontidae includes the type genus

Type genus

In biological classification, a type genus is a representative genus, as with regard to a biological family. The term and concept is used much more often and much more formally in zoology than it is in botany, and the definition is dependent on the nomenclatural Code that applies:* In zoological...

 Rhabdodon, Zalmoxes, and possibly Mochlodon

Mochlodon

Mochlodon is a genus of iguanodont dinosaur from the Late Cretaceous.In 1859 coal mine administrator Pawlowitsch notified the University of Vienna that some fossils had been found in the Gute Hoffnung mine at Muthmannsdorf in Austria...

and Muttaburrasaurus

Muttaburrasaurus

Muttaburrasaurus is a genus of herbivorous ornithopod dinosaur, living in what is now northeastern Australia between 100 and 98 million years ago during the early Cretaceous Period. It has been recovered in some analyses as a member of the iguanodontian family Rhabdodontidae...

. Rhabdodontid fossils have been found in Europe and Australia in formations dating from the Early to Late Cretaceous, 100 to 65 million years ago.