Walking on 2 legs is less efficient and more unstable as compared to 4- legged walking. Why do we say that humans 'evolved' from 4 legs to 2 legs? - Quora
Zoo Atlanta - That whole thing about an ostrich sticking its head in the sand to avoid danger ... now, why would the planet's fastest animal on two legs need to do
![Maryland Zoo on Twitter: "Did you know an Ostrich is the largest living species of bird and the fastest animal on two legs?! #animalfact #mdzoo http://t.co/CJ3FwxWZez" / Twitter Maryland Zoo on Twitter: "Did you know an Ostrich is the largest living species of bird and the fastest animal on two legs?! #animalfact #mdzoo http://t.co/CJ3FwxWZez" / Twitter](https://pbs.twimg.com/media/BPyEA7HCYAAhppH.jpg:large)
Maryland Zoo on Twitter: "Did you know an Ostrich is the largest living species of bird and the fastest animal on two legs?! #animalfact #mdzoo http://t.co/CJ3FwxWZez" / Twitter
![The Ostrich is the world's largest bird. It is also the fastest runner of any bird or other two-legged animal. The flightle… | Flightless bird, Animals, The ostrich The Ostrich is the world's largest bird. It is also the fastest runner of any bird or other two-legged animal. The flightle… | Flightless bird, Animals, The ostrich](https://i.pinimg.com/736x/76/de/7b/76de7bc41a46e875f1ee304debc3e894.jpg)