Phorusrhacos (/ˌfɔːrəsˈrɑːkɒs/ FOR-əs-RAH-koss) is an extinct genus of giant flightless terror birds that inhabited South America during the Miocene epoch.

[2] Among the bones found in the strata of the Santa Cruz Formations (now considered as mainly of mid-Miocene date) was the piece of a mandible which Florentino Ameghino discovered in early 1887 and the same year at first described as that of an edentate mammal which he named Phorusrhacos longissimus.

[6] Phorusrhacos had a skull nearly 65 centimetres (26 in) long, stood nearly 2.4 meters (7 ft 10 in) tall, and probably weighed nearly 130 kilograms (290 lb), as much as a male ostrich.

[7][8] It had very strong legs, capable of running at high speed, stubby, flightless wings, a long neck, and a proportionately large head.

This ended in a huge, hooked beak that could tear through flesh easily, or stab into prey.