Paleontologists studying a 236-million-year-old cynodont fossil from Argentina say they have found the earliest evidence yet of viviparity (live birth) in the evolutionary line that leads to mammals, pushing back the origin of this reproductive strategy by as much as 90 to 95 million years. Life reconstruction of a group of Chiniquodon theotonicus individuals, a pregnant female (left) as well as a female (right) breastfeeding few, relatively large...
