Early radioisotopic age constraints within the Campanian formations with the WIB consisted of K–Ar analyses of biotite and feldspar from interbedded bentonites115,116, with assumed uncertainties to the order of ± 5%, and these analyses are not reviewed even more in this article. Biotite ages, in particular, are viewed as of https://atozbookmark.com/story13159316/top-latest-five-fossils-video-urban-news