ornithischian
noun
or·nith·is·chi·an ˌȯr-nə-ˈthi-skē-ən 
: any of an order (Ornithischia) of herbivorous dinosaurs (such as a stegosaurus) that have the pubis of the pelvis rotated backward to a position parallel and close to the ischium compare saurischian
ornithischian adjective
Example Sentences
Recent Examples on the Web The dinosaur, first described in 2015 as a bizarre, herbivorous theropod, is actually a primitive ornithischian, according to the study — a placement that would strengthen the authors’ argument for rewriting the entire family tree. 
Jon Tennant, Discover Magazine, 24 Jan. 2018 But the saurischians and ornithischians are the two main branches with more specific lineages arrayed along them. Brian Switek, Smithsonian, 8 Dec. 2017 The second group, ornithischians, have pelvic structures superficially similar to modern birds, and include classic armored dinos like Stegasaurus and Triceratops. Jason Daley, Smithsonian, 24 Mar. 2017 Not to mention that the new analysis brings up the question of why theropods and sauropods share air sacs that lightened their skeletons and yet ornithischians – Brian Switek, Scientific American Blog Network, 15 May 2017 The ornithischians, by contrast, included dinosaurs like Stegosaurus and Camptosaurus. Brian Switek, Scientific American Blog Network, 15 May 2017 However, since 2002 paleontologists have unearthed a couple of other ornithischians with primitive bristle or furlike feathers. Gemma Tarlach, Discover Magazine, 10 Apr. 2017 See More
Jon Tennant, Discover Magazine, 24 Jan. 2018 But the saurischians and ornithischians are the two main branches with more specific lineages arrayed along them. Brian Switek, Smithsonian, 8 Dec. 2017 The second group, ornithischians, have pelvic structures superficially similar to modern birds, and include classic armored dinos like Stegasaurus and Triceratops. Jason Daley, Smithsonian, 24 Mar. 2017 Not to mention that the new analysis brings up the question of why theropods and sauropods share air sacs that lightened their skeletons and yet ornithischians – Brian Switek, Scientific American Blog Network, 15 May 2017 The ornithischians, by contrast, included dinosaurs like Stegosaurus and Camptosaurus. Brian Switek, Scientific American Blog Network, 15 May 2017 However, since 2002 paleontologists have unearthed a couple of other ornithischians with primitive bristle or furlike feathers. Gemma Tarlach, Discover Magazine, 10 Apr. 2017 See More Word History
Etymology
New Latin Ornithischia, from ornith- + ischium
First Known Use
1888, in the meaning defined above