'Proboscidea' is an
order containing only one
family of living animals, Elephantidae, the
elephants, with three living
species (
African Bush Elephant,
African Forest Elephant, and
Asian Elephant)
.
During the period of the last
ice age there were more, now
extinct species, including a number of species of the elephant-like
mammoths and
mastodons. Further back in time, in the
late Tertiary, there were many more different types, including the bizarre "
shovel tuskers" like ''
Platybelodon'' and ''
Amebelodon''. The earliest known proboscidean is ''
Phosphatherium'' dating from
paleocene deposits of
Morocco. From the
Eocene, several very primitive proboscideans are known, including the African ''
Numidotherium'', ''
Barytherium'', ''
Moeritherium'' and the
Anthracobunidae from the Indian subcontinent.
Origins
Paleontologists know of about 170 fossil species which they classify as belonging to the Proboscidea (Gr. ''proboskis,'' elephant's trunk, from ''pro,'' before, + ''boskein,'' to feed) group. The oldest dates from the early
Tertiary period, over 50 million years ago. A discovery in December,
2003 has forced a new estimate of the age of
elephant-like species to around 26 million years. Most of these early elephants had four short tusks; two on the upper jaw and two on the lower. ''
Primelephas'', the ancestor of
mammoths and modern
elephants, appeared in the late
Miocene epoch, about 7 million years ago. 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.
References