Cassowaries are ratites, a group believed to have diverged before modern feathered birds evolved. As modern birds, they share characteristics with ancient dinosaur ancestors, such as unfused wishbones and flightlessness. Ratites are considered the closest living relatives of dinosaurs like Tyrannosaurus rex and Velociraptor.
Cassowaries and other ratites have small wings relative to body size, powerful legs with three-toed feet, and flat sternums lacking a keel—features similar to some non-avian dinosaurs. Their feathers are simple and hair-like, lacking the interlocking barbules of flying birds, reminiscent of certain prehistoric dinosaurs.
Cassowaries are not living dinosaurs but modern birds that evolved from a common ancestor with dinosaurs millions of years ago.