Hierarchy classification:

1. top of the aat hierarchies
2. Agents Facet
3. Living Organisms (hierarchy name)
4. living organisms (entities)
5. Eukaryota (domain)
6. Animalia (kingdom)
7. Chordata (phylum)
8. Vertebrata (subphylum)
9. Reptilia (class)
10. Diapsida (subclass)

Narrower term/s

• Saurischia (extinct order)[+]
  • Theropoda (suborder)
• Ornithischia (extinct order)
• raptors (dinosaurs)

Anotations

Scope note:

Members of the taxon of land dwelling archosaurs with an upright gait, by which their legs were straight, perpendicular to the ground, and supported the weight of the body so that the animal could walk or run more easily. Other reptiles and modern lizards had a sprawling gait. Dinosaurs first appeared in the Late Triassic Period about 215 million years ago and thrived worldwide for some 150 million years. Most died out by the end of the Cretaceous Period, about 65 million years ago, but many lines of evidence now show that one lineage evolved into birds about 150 million years ago.