Stegotetrabelodon
Temporal range: Late Miocene to Early Pliocene, 8–4.2 Ma
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Restoration of Stegotetrabelodon syrticus
Stegotetrabelodon molar tooth
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Proboscidea
Family: Elephantidae
Genus: †Stegotetrabelodon
Petrocchi, 1941
Type species
† Stegotetrabelodon syrticus
Petrocchi, 1941
Species
  • S. syrticus Petrocchi, 1941
  • S. orbus Maglio, 1970
  • S. lybicus Petrocchi, 1943
  • S. emiratus Sanders, 2022

Stegotetrabelodon is an extinct genus of primitive elephantid from the Late Miocene to Early Pliocene of Africa, the Arabian Peninsula, and Italy.

Species

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 in southern Italy, which was likely part of Africa during this time.[1]

"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.[2]

Description

An estimate based on the size of limb bones collected from Sahabi suggests that S. syrticus may have reached 4 m (13.1 ft) in shoulder height and 11–12 tonnes (12.1–13.2 short tons) in weight,[3] with a similar estimate of 3.7 m (12.1 ft) and 10–11 tonnes (11.0–12.1 short tons) made for S. emiratus.[1] 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.[4] The lower tusks are the longest known among proboscideans, reaching a length of 2.2 metres (7.2 ft) in S. syrticus, though they weighed only around 12.5 kilograms (28 lb), with the upper tusks also being large, reaching a length of 2.8 metres (9.2 ft) and weight exceeding 40 kilograms (88 lb) in S. syrticus.[5]

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"[6] in the Western Region[7] of the Emirate of Abu Dhabi, the United Arab Emirates. The longest of these tracks extend for 290 m (950 ft) and 170 m (560 ft).[8] These tracks suggest that like modern elephants, Stegotetrabelodon lived in herds.[9]

References

  1. ^ a b Sanders, William J. (2022), Bibi, Faysal; Kraatz, Brian; Beech, Mark J.; Hill, Andrew (eds.), "Proboscidea from the Baynunah Formation", Sands of Time, Cham: Springer International Publishing, pp. 141–177, doi:10.1007/978-3-030-83883-6_10, ISBN 978-3-030-83882-9, retrieved 2024-01-03
  2. ^ Wang, Shi-Qi; Saegusa, Haruo; Duangkrayom, Jaroon; He, Wen; Chen, Shan-Qin (December 2017). "A new species of Tetralophodon from the Linxia Basin and the biostratigraphic significance of tetralophodont gomphotheres from the Upper Miocene of northern China". Palaeoworld. 26 (4): 703–717. doi:10.1016/j.palwor.2017.03.005.
  3. ^ Larramendi, A. (2016). "Shoulder height, body mass and shape of proboscideans" (PDF). Acta Palaeontologica Polonica. 61. doi:10.4202/app.00136.2014. S2CID 2092950.
  4. ^ Athanassiou, Athanassios (2022), Vlachos, Evangelos (ed.), "The Fossil Record of Continental Elephants and Mammoths (Mammalia: Proboscidea: Elephantidae) in Greece", Fossil Vertebrates of Greece Vol. 1, Cham: Springer International Publishing, pp. 345–391, doi:10.1007/978-3-030-68398-6_13, ISBN 978-3-030-68397-9, S2CID 245067102, retrieved 2023-11-21
  5. ^ Larramendi, Asier (2023-12-10). "Estimating tusk masses in proboscideans: a comprehensive analysis and predictive model". Historical Biology: 1–14. doi:10.1080/08912963.2023.2286272. ISSN 0891-2963.
  6. ^ Mauguit, Quentin (2012-02-23). "Des empreintes de 7 millions d'années racontent les éléphants d'autrefois". Futura (in French). Retrieved 2018-10-11.
  7. ^ "Des empreintes de 7 millions d'années racontent les éléphants d'autrefois". Futura (in French). Retrieved 2018-10-11.
  8. ^ Hill, Andrew; Bibi, Faysal; Beech, Mark; al-Tikriti, Walid Yasin (January 2012). "Before archaeology: Life and environments in the Miocene of Abu Dhabi". ResearchGate. p. 27.
  9. ^ Bibi, Faysal; Kraatz, Brian; J. Beech, Mark; Hill, Andrew (2022), Bibi, Faysal; Kraatz, Brian; Beech, Mark J.; Hill, Andrew (eds.), "Fossil Trackways of the Baynunah Formation", Sands of Time, Cham: Springer International Publishing, pp. 283–298, doi:10.1007/978-3-030-83883-6_17, ISBN 978-3-030-83882-9, retrieved 2024-01-18
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