Tag: Evolution
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Paleontologists trace the evolution of tusks to toothy Triassic creatures
An artist’s conception shows a type of dicynodont known as Dicynodon. (Illustration by Marlene Hill Donnelly) Dental exams conducted on fossils from more than 200 million years ago suggest that the earliest true tusks were sported by breeds of weird-looking creatures known as dicynodonts. The evidence, laid out today in the Proceedings of the Royal…
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Scientists say supernovae spread fallout when human ancestors walked the earth
An artist’s impression shows a supernova explosion in its prime. (Credit: Greg Stewart / SLAC) Researchers say they’ve found evidence of supernova explosions that spewed radioactive fallout over Earth during the age when humanity’s ancestors were evolving into upright-walking, big-brained creatures. One of two studies published in the journal Nature identifies deposits of radioactive iron-60 in deep-sea cores extracted…