Q. What is the only flightless diving bird?
A. The penguin - although there were ancient birds that may have dived for food but couldn't fly.
Most scientists agree that the 17 or 18 species of penguin we know today evolved from an airborne ancestor 5 million to 40 million years
ago.
The first penguin fossil was found in New Zealand in the mid-1850s and is now in the British Museum of Natural History.
Although penguin fossils are rare and only fragments of skeletons have been found, the biggest ancient penguin may have stood almost 1.8m (6ft).
Scientists recognise 32 species of extinct penguins but don't agree on where the name originated.
One theory is that it refers to penguin portliness (fat is penguigo in Spanish and pinguis in Latin), but the popular consensus is that penguin was the name used for the now-extinct great auk, which was mistakenly thought to be an early ancestor of penguins.
Antarctica's emperor penguin is the largest modern species, growing to about 1.2m (4ft) tall.
NZ Penguins
* Email your Big Questions on space, science, conservation and environment to Your World for an answer.
* anne_beston@nzherald.co.nz
Further reading
nzherald.co.nz/environment
