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Brontornis

Brontornis was a genus of giant flightless predatory birds that lived in Patagonia. The only species currently accepted as valid is B. burmeisteri. It has traditionally been placed in the family Phorusrhacidae, nicknamed "Terror Birds" for their large size and predatory lifestyle, and more precisely to the subfamily Brontornithinae, which contained extremely large and very heavyset forms.