What was the largest extinct bird called?

Mammals

Although the most popularized large mammal was the Woolly Mammoth, the largest extinct mammal is the indricothere, a giant prehistoric ancestor of the rhinoceros, which was far bigger than any of the elephants.

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Sauropods (dinosaurs)

The sauropod called Bruhathkayosaurus is estimated at "only" 144 feet long (45 m), but it would have been the heaviest known land animal, heavier at 140 tons than most blue whales.

The physically "biggest" could be Amphicoelias, a Diplodocid about which little is known, but which may have been up to 200 feet (60 m) in length.

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