before the asteroid impact that wiped out the dinosaurs. the study, led by researchers at northwestern university, is the first to measure the calcium isotope composition of fossilized clam and snail shells, which date back to the cretaceous-paleogene mass extinction event. the researchers found that — in...
before the asteroid impact that wiped out the dinosaurs. the study, led by researchers at northwestern university, is the first to measure the calcium isotope composition of fossilized clam and snail shells, which date back to the cretaceous-paleogene mass extinction event. the researchers found that — in...