1. Fanciful composite Vertebral articulation (Body) Rib articulation

2. Frog sacral (cervical) Sternum is associated with pectoral girdle (not with thoracic ribs)

3. Alligator Ribs meet at sternum Have short ribs Lack ribs Chevron bones Sternum is single anteriorly, splits posteriorly

4. Turtle Turtle thoracic vertebrae, sacrum and first caudal vertebrae are fused to the carapace. Turtles lack true lumbar vertebrae.

5. Pigeon Ribs meet sternum flexible Fused caudal vertebrae Sternum is large and ossified, with a prominent keel

6. Cat Anterior Articulate with ribs 7 cervical Posterior 3-5 vertebrae 3-40 Sternum is a series of separate bones (jointed rod) Human: 3-part plate

7. Human 7 12 5 5 fused 3-5 fused

8. In amphibians, ribs are reduced/lacking. Frogs have only sacral ribs. Frog sacral (cervical) Sternum is associated with pectoral girdle (not with thoracic ribs)

9. Turtles have no cervical ribs. The thoracic ribs are long, flat, and fused to the carapace. Sacral ribs unite with the pelvic girdle. Turtles have no sternum

10. In crocodilians, ribs are double-headed. Most vertebrae bear ribs. Thoracic vertebrae have 2-part ribs. Alligator Ribs meet at sternum Have short ribs Lack ribs 2 fused Chevron bones Sternum is single anteriorly, splits posteriorly

11. In birds, all 5 groups of vertebrae bear ribs. Anterior thoracic ribs unite with sternum. Thoracic ribs have 2 parts. Pigeon Ribs meet sternum flexible Fused caudal vertebrae Sternum is large and ossified, with a prominent keel

12. Cat Anterior Articulate with ribs 7 cervical Thoracic vertebrae have 2-part ribs. Mammals lack ribs in the lumbar and caudal regions. Posterior Sternum is a series of separate bones (jointed rod) In human, the sternum is a 3-part plate

13. The human sternum has 3 parts