120-million-year-old mammal may have replaced its teeth throughout life

New Scientist reports that Dongoconodon platycauda, a 120-million-year-old mammal fossil found in China, had a streamlined appearance and feet remarkably like a platypus’s. Its teeth appear to have been replaceable throughout life, unlike the two sets most modern mammals get. Researchers say the animal’s unusual mix of traits offers a window into early mammal evolution.