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 Birds Extinct Birds Extinct Birds (complete title: Extinct birds. An attempt to unite in one volume a short account of those Birds which have become extinct in historical times—that is, within the last six or seven hundred years. To which are added a few which still exist, but are on the verge of extinction.) is a book by Walter Rothschild which covers globally extinct and rare birds as well as hypothetical extinct species which include bird taxa whose existence is only based on written or oral reports or on paintings. The accounts of the extinct bird taxa are based on Rothschild's