Early radioisotopic age constraints to the Campanian formations of the WIB consisted of K–Ar analyses of biotite and feldspar from interbedded bentonites115,116, with assumed uncertainties around the get of ± five%, and these analyses are usually not talked about further here. Biotite ages, specifically, are regarded of questionable precision by https://fatallisto.com/story2285638/fossil-record-secrets