Linked from
The 57 pages that link to Biostratigraphy, each with the reason it gives.
Historical geologyRelated: Fossil succession links strata of similar age across distant regions.
PurgatoriusRelated: Fossil-bearing layers help establish when Purgatorius lived.
TurritellidaeRelated: Recognizable turritellid fossils can assist correlation of marine strata.
Geologic recordRelated: Fossil succession helps establish the sequence of strata across regions.