Mammoth construction of the Great Pyramid of ancient Egypt. The earliest known proboscideans, the clade that contains the elephants, existed about 55 million years ago around the Tethys Sea area. The closest relatives of the Proboscidea are the sirenians and the hyraxes. The family Elephantidae is known to have existed six million years ago in Africa, and includes the living elephants and the mammoths. Among many now extinct clades, the mastodon is only a distant relative of the mammoths, and part of the separate Mammutidae family, which diverged 25 million years before the mammoths evolved. The following cladogram shows the placement
Extinct in the wild among aquarists for some time, but hobbyist stocks have declined quite a lot more recently, placing its survival in jeopardy. However, the ultimate purpose of preserving biodiversity is to maintain ecological function. When a species exists only in captivity, it is ecologically extinct. Reintroduction is the deliberate release of species into the wild, from captivity or relocated from other areas where the species survives. This may be an option for certain species that are endangered or extinct in the wild. However, it may be difficult to reintroduce EW species into the wild, even if their natural habitats were restored, because