Ornithischian

Description

Ornithischia is a very large and diverse group of dinosaurs, with members known from all continents, habitats, and a very large range of sizes. They are primarily herbivorous browsers or grazers, but some members may have also been opportunistic omnivores. Ornithischians are united by multiple features of the skull, teeth, and skeleton, including especially the presence of a predentary and palpebral, an increased number of sacral vertebrae, the absence of gastralia, and an opisthopubic pubis. Early ornithischians ranged around 1–2 m (3.3–6.6 ft) in length, with them increasing in size over time so that the largest armoured ornithischians were around 7.5 m (25 ft) and 9 t (8.9 long tons; 9.9 short tons), the largest horned ornithischians were around 8.5 m (28 ft) and 11 t (11 long tons; 12 short tons), and the largest crested ornithischians were around 15 m (49 ft) and 13.5 t (13.3 long tons; 14.9 short tons).