Assertion: shelled cephalopod | /r/CapableOf | become extinct
Facets:
value: at the end of the cretaceous
type: TEMPORAL
Source sentences:
text: This pressure may have increased as a result of the increased complexity of fish in the late Palaeozoic, increasing the competitive pressure.(p289) Internal shells still exist in many non-shelled living cephalopod groups but most truly shelled cephalopods, such as the ammonites, became extinct at the end of the Cretaceous.