Flightless bird
Flightless birds are birds that, through evolution, lost the ability to fly. There are over 60 extant species, including the well-known ratites and penguins. The smallest flightless bird is the Inaccessible Island rail. Wikipedia
Speed: Emu: 31 mph, Common ostrich: 43 mph, and Emperor penguin: 3.7 – 5.6 mph
Representative species