Dryosauridae

Dryosauridae is an extinct family of herbivorous bipedal ornithopod dinosaurs, first proposed by Milner & Norman in 1984. They are known from Middle Jurassic to Early Cretaceous rocks of Africa, Europe, and North America.
Dryosauridae was first proposed in 1984 by British paleontologists Andrew R. Milner and David B. Norman, as a family to unite the early ornithopods Dryosaurus, Valdosaurus, and possibly Parksosaurus and Mochlodon. Milner and Norman separated these taxa from the family Hypsilophodontidae as they showed greater similarity with hadrosaurids and iguanodontids. The spelling had previously been used as a typographical error by Deraniyagala in 1939 for Dyrosauridae. Dryosaurids were cursorial animals adapted for running.

Classification

Until recently, many dryosaurids have been regarded as dubious or as species of the type member, Dryosaurus. However, more recent studies redescribe these genera as valid. Under the Phylocode, Madzia et al. formally defined Dryosauridae as "the largest clade containing Dryosaurus altus but not Iguanodon bernissartensis." The cladogram below follows their chosen reference phylogeny, taken from the description of Orthomerus dolloi.