In Argentina, one fossil bone from a 236-million-year-old cynodont contained a rare clue about birth. Researchers found its newborn size resembled mammals, suggesting live birth evolved 95 million years earlier than thought

Wait 5 sec.

New fossil evidence challenges the long-held belief that ancient cynodonts laid eggs. A recent study found compelling proof that Chiniquodon theotonicus gave birth to live young. This discovery pushes the evolutionary timeline for live birth back by approximately ninety-five million years. Such an adaptation offered better protection for developing embryos in harsh Triassic environments. This finding suggests some early mammalian ancestors were more like modern mammals than previously assumed.