Madagascar is often called the eighth continent and is so distinct that primate scientists divide the world into four regions: the Americas, South Asia, mainland Africa, and the Island of Madagascar. It is the world's only place to find the wild lemur. Madagascar was also home to the elephant bird, the largest bird that ever lived, which laid the largest egg ever known on Earth. Its eggs held well over two gallons of liquid, about 150 times the volume of a chicken egg, and the extinct flightless bird stood over ten feet high, weighed 1,000 pounds, and survived on the island as recently as a few hundred years ago.