Proboscidea is an order containing only one family of living animals, the elephants.
During the period of the ice age there were more, now extinct species, including the elephant-like mammoth and mastodon and the "shovel tuskers", the platybelodon and amebelodon.
Origins
Paleontologists know of 170 fossils specimens which they classify as belonging to this group. The oldest dates from the Tertiary period, over 50 million years ago. A recent discovery (December 2003) has forced a new estimate of the age of elephant-like species to around 26 million years. Modern elephants appeared around 7 million years after the end of the Miocene period. The evolution of the elephant-like animals mainly concerned the proportions of the cranium and jaw and the shape of the tusks and molar teeth.