A baby in Alabama, who weighed less than a pound at birth, has been named the most premature baby to survive by Guinness World Records. Curtis Zy-Keith Means was born at 21 weeks at the University of Alabama at Birmingham hospital when his mother, Michelle "Chelly" Butler, underwent emergency surgery to deliver, according to Guinness. When Butler gave birth to her son on July 5, 2020, Curtis weighed just 14.8 oz, or 420 grams. Curtis' due date was originally set to November 11 of that year, making him nearly 19 weeks early. Now, the 16-month-old is healthy and happy. After his birth, Curtis underwent treatment, responded "extraordinarily well," per Guinness, and made an "exceptional" recovery. Curtis' remarkable progress was bittersweet for Butler, who delivered twins – both Curtis and his sister, C'Asya – July 5. C'Asya was born less developed than her brother, and died one day after she was born, according to Guinness. In his two-decade career, Curtis’ doctor said he's never seen anything like his case. Curtis beat out the previous record holder for most mature baby to survive, Richard Hutchinson, who weighed just 11.9 oz when he was born June 5, 2020.