1. Pelagornis sandersi – It’s the biggest bird that ever lived. Its wings measured approximately 24 feet, and the fossil was discovered in 1983 in South Carolina. Mostly, it was flying over the oceans.

    Image source: unbelievable-facts.com/
    Image source: unbelievable-facts.com
  2. Teratornis – It was 30 inches tall and lived in North America. Archeologists discovered over 100 fossils all over the continent. Its wings measured 20 feet.

    Image source: unbelievable-facts.com
    Image source: unbelievable-facts.com
  3. Physornis fortis – This bird was a predator that lived in Argentina. Although it is considered to be a bird, it couldn’t fly.

    Image source: smashinglists.com
    Image source: smashinglists.com
  4. Paraphysornis – It used to be one of the most dangerous birds in the world. It couldn’t fly, and it measured more than two meters.

    Image source: smashinglists.com
    Image source: smashinglists.com
  5. Gastornis – This bird lived almost 50 million years ago, in North America and Europe. They lived on plants, but their defense mechanism was on point.

    Image source: mentalfloss.com
    Image source: mentalfloss.com
  6. Andalgalornis steulleti – This species was extremely dangerous and a feared predator. Its head was really thin but seemed big when seen from the side.

    Image source: mentalfloss.com
    Image source: mentalfloss.com
  7. Haast’s eagle – This bird is the biggest eagle that ever lived, and got extinct after 1400 CE. It was feeding mostly on other birds.

    Image source: unbelievable-facts.com
    Image source: unbelievable-facts.com
  8. Phorusrhacos Longissimus – This species measured more than 2.5 m and about 125 kg. It was also a predator.

    Image source: smashinglists.com
    Image source: smashinglists.com
  9. Kelenken – This bird’s head was so big so that it could use it for defense. It lived 15million years ago as one of the most terrifying birds ever.

    Image source: smashinglists.com
    Image source: smashinglists.com
  10. Dinornis – It lived in New Zealand and got extinct due to the fact that the Maori and the Haast’s eagles were hunting it. It weighed about 500 pounds.

    Image source: mentalfloss.com
    Image source: mentalfloss.com