Definition that contains keeled
- flying bird birds having keeled breastbones for attachment of flight muscles
- mononychus olecranus a turkey-sized long-legged fossil 75 million years old found in the Gobi Desert having bird-like fused wrist bones and keeled breastbone and a long tail resembling a dinosaur's; short forelimbs end in a single claw instead of wings; classification as bird or dinosaur is in dispute
- carinate birds having keeled breastbones for attachment of flight muscles
- sinornis sparrow-sized fossil bird of the Jurassic period to the Cretaceous period having a keeled breastbone and vestigial tail; found in China; considered possibly the second most primitive of all birds
- carinate bird birds having keeled breastbones for attachment of flight muscles