Assertion: rib cage's rib | /r/AtLocation | vertebra
Facets:
value: in the primitive condition
type: OTHER
Source sentences:
text: In the primitive condition, ribs were attached to all vertebrae; this is still true in some reptiles (e.g., snakes), but in mammals only thoracic vertebrae carry ribs.
text: The eleventh and twelfth ribs are attached to the vertebrae only.