Amphicoelias was the name given to two giant leg bones found in the 1800s. Scientists said the bones were from an unidentified dinosaur. The estimation for how big the whole dinosaur would be was about as big as two blue whales, making it the biggest animal ever. But before the bones could be proven 100 percent real, they mysteriously disappeared.


Scientists now think that Amphicoelias could have just been a bone from a recently discovered sauropod, and at that time they did not know. The estimation must have been wrongly calculated.