Rhabdodontids were
herbivorous ornithopod dinosaurs from the
Cretaceous Period. Rhabdodontids were similar to large, robust "
hypsilophodonts", with deep skulls and jaws. The
family was first proposed by
David B. Weishampel and colleagues in 2002. The rhabdodontids were defined as "the most recent common ancestor of
Zalmoxes robustus and
Rhabdodon priscus and all the descendants of this common ancestor". In 2005,
Paul Sereno defined the family as "the most inclusive
clade containing
Rhabdodon priscus but not
Parasaurolophus walkeri". The Rhabdodontidae includes the
type genus Rhabdodon,
Zalmoxes,
Mochlodon and possibly
Muttaburrasaurus. Rhabdodontid fossils have been found in Europe and Australia in formations dating from the Early to Late Cretaceous, 100 to 66 million years ago. Ősi
et al. (2012) proposed that
Rhabdodon underwent gigantism on the mainland, as opposed to
Zalmoxes and
Mochlodon experiencing nanism on island habitats. In 2013, Darren Naish discovered a tiny rhabdodont tibia from Sebeș, Romania, turning out to be the smallest known; a paper (Brusette et
al 2013.) later in the same year identified it as
Zalmoxes, cf.
Z. shqiperorum.