If the competition were about size alone, the ostrich would take the crown as the world’s largest bird. Standing up to 2.7 meters (9 feet) tall and weighing as much as 150 kilograms (330 pounds ...

But elephant birds, who lived more than 1,200 years ago, were likely the biggest birds to ever exist at over 1,500 pounds. Some even clocked in around 1,900 pounds, according to Scientific American.

But elephant birds, who lived more than 1,200 years ago, were likely the biggest birds to ever exist at over 1,500 pounds. Some even clocked in around 1,900 pounds, according to Scientific American.