I'm not particularly thrilled by the idea of rooster-sized dinosaurs. My parents had an egg farm (free range) when I was a toddler, and the roosters attacked me at every opportunity. Think in terms of the early scene in Jurassic Park where the raptor's claw is demonstrated.
Spielberg's raptors were modeled after the behavior of fowl. I've seen those hunting techniques up close.
Domestic roosters can't fly. A flying velociraptor is more frightening than a running raptor.
It's great fun when you cut their heads off and they insist on believing it's still attached while running 'headlong' into a barn door.
(I needed the catharsis of that ghoulish vision.)