Assertion: p tr extinction | /r/CapableOf | form the boundary
Facets:
value: between between
type: LOCATION
Source sentences:
text: Tr extinction, the P–T extinction, the End-Permian Extinction, and colloquially as the Great Dying, formed the boundary between the Permian and Triassic geologic periods, as well as between the Paleozoic and Mesozoic eras, approximately 252 million years ago.