Although the whole family Poeciliidae is known as "live bearers", there are egg-scattering species with external fertilization in addition to the true live-bearing viviparous and ovoviviparous species, which have internal fertilization and the eggs hatch before being laid, so the female gives birth to live young. All African species are egg-layers, and (with the exception of the members of the genus Tomeurus) all American species are live-bearers. This distribution suggests Poeciliidae antedate the split between Africa and South America 100 million years ago, and live-bearing subsequently evolved in South America. Poeciliids colonized North America through the Antilles while they were connected 44 million years ago. Poeciliids then moved to Central America by the Aves land bridge. When Sou