What is "paleopsilopterus"

Paleopsilopterus is an extinct genus of giant flightless predatory birds within Cariamiformes. It is usually attributed to the subfamily Psilopterinae of the family Phorusrhacidae, or "terror birds", though doubts about such an identity have arisen multiple times. It lived 60 million years ago in Brazil during the late Paleocene. The only known species is Paleopsilopterus itaboraiensis.