ornithischia

from The Century Dictionary.

• An order of Dinosauria containing the Iguanodon and other species which have the bones of the pelvis arranged much like those of a bird. It is practically equivalent to the Ornithopoda of other writers. Contrasted with Saurischia.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun extinct terrestrial reptiles having bird-like pelvises: armored dinosaurs (thyreophorans); boneheaded and horned dinosaurs (marginocephalians); duck-billed dinosaurs (euronithopods)