EVOLUTION

There were over 161 members of the order Proboscidea, but they are now extinct. The earliest signs of proboscides found in the late Paleocene Era were named the African Eritherium and Phosphatherium. These were in the first radiation of the evolutionary track for the modern day elephant. The Eocene included Numidotherium, Moeritherium, and Barytherium. These animals were found in modern day Africa and were relatively small and aquatic. Later on, genera such as Phiomia and Palaeomastodon arose and likely inhabited forests and open woodlands. Proboscidean diversity declined during the Oligocene.

The second radiation was represented by the emergence of the gomphotheres in the Miocene. They originated in Africa and were able to spread to every continent except Australia and Antarctica. The main members of this group included Gomphotherium and Platybelodon.

The third radiation started in the late Miocene and led to the arrival of the elephantids. The African Primelephas gomphotheroides gave rise to Loxodonta (remained in Africa), Mammuthus (Eurasia), and Elephas (North America). At the same time, the stegodontids, which were another proboscidean group, spread throughout Asia (this included the Indian subcontinent, China, southeast Asia and Japan). Mammuthus evolved into several species, including the well-known woolly mammoth. In the Late Pleistocene, most proboscidean species vanished during the Quaternary glaciation which killed off 50% of genera weighing over 5 kg (11 lb) worldwide.

DWARF SPECIES

Several species of the proboscidea lived on isolated islands and experienced a form of dwarfism called insular dwarfism. Scientists believe that these species became smaller due to lack of large or viable predator populations and limited resources. Dwarf proboscideans were believed to have lived in Indonesia, the Channel Islands of California, and several islands of the Mediterranean.
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