Although ornithischian (bird-hipped) dinosaurs share the same hip structure as birds, birds actually originated from the saurischian (lizard-hipped) dinosaurs if the dinosaurian origin theory is correct.
Based on the current distribution of fossil evidence, it appears that feathers were an ancestral dinosaurian trait, though one that may have been selectively lost in some species.
The long-necked herbivores attained sizes no other dinosaurian or mammalian group has ever approached on land; part of sauropod success as giants may be tied to limb morphology and specializations.
The geologists also found that the limestone bed containing the fossilized eggs was underlain by a layer of coarse sandstone and conglomerate with abundant dinosaurian fossil bones.
Dinosaurian growth patterns and rapid avian growth rates.
The category covers all the non-dinosaurian reptiles which are often erroneously considered to be dinosaurs, such as the seafaring varieties of plesiosaurs and the flying pterosaurs.
Several researchers classified the remains as non-dinosaurian.
However, only a few scientists still debate the dinosaurian origin of birds, suggesting descent from other types of archosaurian reptiles.
