Elephant birds are members of the family Aepyornithidae which consists of four genera - Eremopezus, Stromeria, Mullerornis, and Aepyornis. The first two of these are the earliest members, dating back to 60 million years. The latter two genera are estimated to be not more than 2 million years old.
The birds had a physical appearance similar to that of ostriches, with small heads, vestigial wings, and long, powerful legs. The largest species, Aepyornis maximus, stood over 3 metres tall and weighed approximately 450 kg. It is likely that the legendary roc of the Thousand and One Nights was based on this creature.
The family Aepyornithidae inhabited North Africa and Madagascar, although Aepyornis and Mullerornis remains have been found only in Madagascar. The birds may have survived until as recently as 1649, and been driven to extinction by hunting.
Eggs laid by elephant birds thousands of years ago are still being found buried in sand on beaches. The largest one found has a circumference of about one metre and a capacity of 9 litres.