''Stegotetrabelodon'' ("four roofed tusked-tooth") is an extinct genus of primitive elephantid from the Late

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

to Early

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

, the

Arabian Peninsula The Arabian Peninsula (, , or , , ) or Arabia, is a peninsula in West Asia, situated north-east of Africa on the Arabian plate. At , comparable in size to India, the Arabian Peninsula is the largest peninsula in the world. Geographically, the ...

, and Italy. It is the earliest and most primitive member of the family, notably retaining long lower tusks, which are the longest known of any proboscidean.

Species and evolution

''Stegotetrabelodon'' is suggested to have probably evolved from the "tetralophodont gomphothere" '' Tetralophodon''. The earliest species ''S. emiratus'' is known from the Late Miocene Baynunah Formation of the United Arab Emirates on the Arabian Peninsula, dating to around 8-6 million years ago. ''S. orbus'' is known from the Late Miocene-Early Pliocene in East Africa (Kenya, Uganda), spanning from around 7.5 million years ago to possibly as late as 4.2 million years ago. The species ''S. syrticus'' is known from the Sahabi site in Libya, dating to around 6.8–5.3 million years ago, with remains of the species also reported from the Late Miocene of

Calabria Calabria is a Regions of Italy, region in Southern Italy. It is a peninsula bordered by the region Basilicata to the north, the Ionian Sea to the east, the Strait of Messina to the southwest, which separates it from Sicily, and the Tyrrhenian S ...

in southern Italy, which was likely part of Africa during this time. "''Stegotetrabelodon" maluvalensis'' from the Late Miocene of Pakistan is now placed in '' Stegolophodon,'' while "''Stegatetrabelodon''" ''gigantorostris'' from the Late Miocene of China is now placed in ''Tetralophodon''.

Description

An estimate based on the size of limb bones collected from Sahabi suggests that ''S. syrticus'' may have reached in shoulder height and in weight, with a similar estimate of and made for ''S. emiratus.'' In comparison to later elephantids, ''Stegotetrabelodon'' has several primitive features, including the retention of permanent premolar teeth, an elongated mandibular symphysis and large lower tusks, shared with its gomphothere ancestors. The lower tusks are the longest known among proboscideans, reaching a length of in ''S.'' ''syrticus'', though they weighed only around , with the upper tusks also being large, reaching a length of and weight exceeding in ''S. syrticus''.

Ecology

In December 2006, a small contingent of Emirates Natural History Group members found several sets of proboscidean footprints thought to have probably been produced by ''Stegotetrabelodon'' preserved in a large calcareous exposure between the sand dunes of "Mleisa 1" in the Western Region of the Emirate of Abu Dhabi, the

United Arab Emirates The United Arab Emirates (UAE), or simply the Emirates, is a country in West Asia, in the Middle East, at the eastern end of the Arabian Peninsula. It is a Federal monarchy, federal elective monarchy made up of Emirates of the United Arab E ...

. The longest of these tracks extend for and . These tracks suggest that like modern elephants, ''Stegotetrabelodon'' lived in herds.

References

* * {{Taxonbar, from=Q310824 Prehistoric elephants Miocene proboscideans Pliocene proboscideans Gomphotheres Prehistoric placental genera Neogene mammals of Africa Neogene mammals of Europe Neogene mammals of Asia Fossil taxa described in 1941