Palaeoloxodon namadicus

From Bharatpedia, an open encyclopedia


Asian straight-tusked elephant
Palaeoloxodon namadicus.JPG
Skull at the Indian Museum, Kolkata
Scientific classification edit
: [[Template:Taxonomy/Palaeoloxodon]]
Species:
Binomial name
Template:Taxonomy/PalaeoloxodonPalaeoloxodon namadicus
(Falconer & Cautley, 1846)

Palaeoloxodon namadicus or the Asian straight-tusked elephant, is an extinct species of prehistoric elephant known from the early Middle to Late Pleistocene of the Indian subcontinent, and possibly also elsewhere in Asia.

Life restoration

Some authorities regard it to be a subspecies of Palaeoloxodon antiquus, the European straight-tusked elephant, due to extreme similarities of the tusks.[1] Their skull structure was also different from that of a modern elephant. The grouping of this genus is supported by cranial synapomorphies with other species of Palaeoloxodon, which includes a large crest at the top of the skull that anchored the splenius muscles used to support the head. Later research suggested that P. namadicus can be distinguished from P. antiquus by its less robust limb bones and more stout cranium.[2]

Based on the stable isotope ratioes of carbon and oxygen and the morphology of their teeth, it is suggested that P. namadicus tended towards a grazing diet, as opposed to the sympatric Stegodon and Elephas species, which tended more towards browsing.[3]

Palaeoloxodon namadicus is thought to have become extinct during the Late Pleistocene, making it one of four megafaunal species native to India known to have become extinct during the Late Pleistocene, alongside fellow proboscidean Stegodon namadicus, the equine Equus namadicus, and a species of hippopotamus belonging to the genus Hexaprotodon.[4][5] A late record of approximately 56,000 years Before Present is known from the banks of the Dhasan River on the Ganga plain in Uttar Pradesh.[6] In 2015, a study based on extensive research of fragmentary leg bone fossils suggested that P. namadicus may have been the largest land mammal ever,[7] but this requires reexamination.[8]

Remains possibly attributable to P. namadicus have also been reported across Southeast Asia and China.[9] However, the status of Chinese Palaeoloxodon is unresolved, with other authors considering the remains to belong to P. naumanni (otherwise known from Japan) or the separate species P. huaihoensis. The postcranial remains of Palaeoloxodon from China are substantially more robust than Indian P. namadicus and in many respects are more similar to those of P. antiquus.[2] Remains attributed to P. namadicus or a similar form have been reported from the island of Sulawesi in Indonesia, similar in size to that reported for the Indian subcontinent.[10]

Size[edit]

Size comparison of P. namadicus with human and Paraceratherium.

Several studies have attempted to estimate the size of the Asian straight-tusked elephants, as well as other prehistoric proboscideans, usually using comparisons of thigh bone length and knowledge of relative growth rates to estimate the size of incomplete skeletons.

One partial skeleton found in India in 1905 had thigh bones that likely measured 165 centimetres (5.41 ft) when complete, suggesting a total shoulder height of 4.5 metres (14.8 ft) for this individual elephant.

Two partial thigh bones were found in the 19th century and would have measured 160 cm (5.2 ft) when complete. A fragment from the same locality was said to be almost a quarter larger; volumetric analysis then yields a size estimate of 5.2 metres (17.1 ft) tall at the shoulder and 22 tonnes (24.3 short tons) in body mass; however, this estimate based on the "distal femur portion" requires reexamination, as the author himself could only suspect that "fossils are likely stored in the Indian Museum of Kolkata; until such a collection can be revised, this size estimate will remain speculative."[8]

References[edit]

  1. Ferretti, M.P. (May 2008). "The dwarf elephant Palaeoloxodon mnaidriensis from Puntali Cave, Carini (Sicily; late Middle Pleistocene): Anatomy, systematics and phylogenetic relationships". Quaternary International. 182 (1): 90–108. Bibcode:2008QuInt.182...90F. doi:10.1016/j.quaint.2007.11.003.
  2. 2.0 2.1 Larramendi, Asier; Zhang, Hanwen; Palombo, Maria Rita; Ferretti, Marco P. (February 2020). "The evolution of Palaeoloxodon skull structure: Disentangling phylogenetic, sexually dimorphic, ontogenetic, and allometric morphological signals". Quaternary Science Reviews. 229: 106090. Bibcode:2020QSRv..22906090L. doi:10.1016/j.quascirev.2019.106090.
  3. Patnaik, Rajeev; Singh, Ningthoujam Premjit; Paul, Debajyoti; Sukumar, Raman (2019-11-15). "Dietary and habitat shifts in relation to climate of Neogene-Quaternary proboscideans and associated mammals of the Indian subcontinent". Quaternary Science Reviews. 224: 105968. doi:10.1016/j.quascirev.2019.105968. ISSN 0277-3791.
  4. Jukar, A.M.; Lyons, S.K.; Wagner, P.J.; Uhen, M.D. (January 2021). "Late Quaternary extinctions in the Indian Subcontinent". Palaeogeography, Palaeoclimatology, Palaeoecology. 562: 110137. doi:10.1016/j.palaeo.2020.110137.
  5. Turvey, Samuel T.; Sathe, Vijay; Crees, Jennifer J.; Jukar, Advait M.; Chakraborty, Prateek; Lister, Adrian M. (January 2021). "Late Quaternary megafaunal extinctions in India: How much do we know?". Quaternary Science Reviews. 252: 106740. doi:10.1016/j.quascirev.2020.106740.
  6. Ghosh, Rupa; Sehgal, R. K.; Srivastava, Pradeep; Shukla, U. K.; Nanda, A. C.; Singh, D. S. (November 2016). "Discovery of Elephas cf. namadicus from the late Pleistocene strata of Marginal Ganga Plain". Journal of the Geological Society of India. 88 (5): 559–568. doi:10.1007/s12594-016-0521-7. ISSN 0016-7622.
  7. "An Ancient Elephant May Have Been Biggest Land Mammal Ever". 2015-07-17. Retrieved 2017-04-21.
  8. 8.0 8.1 Larramendi, Asier (2015). "Proboscideans: Shoulder Height, Body Mass and Shape". Acta Palaeontologica Polonica. doi:10.4202/app.00136.2014.
  9. Louys, Julien; Curnoe, Darren; Tong, Haowen (January 2007). "Characteristics of Pleistocene megafauna extinctions in Southeast Asia". Palaeogeography, Palaeoclimatology, Palaeoecology. 243 (1–2): 152–173. doi:10.1016/j.palaeo.2006.07.011.
  10. Geer, Alexandra A. E.; Bergh, Gerrit D.; Lyras, George A.; Prasetyo, Unggul W.; Due, Rokus Awe; Setiyabudi, Erick; Drinia, Hara (August 2016). "The effect of area and isolation on insular dwarf proboscideans". Journal of Biogeography. 43 (8): 1656–1666. doi:10.1111/jbi.12743. ISSN 0305-0270.
Information red.svg
Scan the QR code to donate via UPI
Dear reader, We kindly request your support in maintaining the independence of Bharatpedia. As a non-profit organization, we rely heavily on small donations to sustain our operations and provide free access to reliable information to the world. We would greatly appreciate it if you could take a moment to consider donating to our cause, as it would greatly aid us in our mission. Your contribution would demonstrate the importance of reliable and trustworthy knowledge to you and the world. Thank you.

Please select an option below or scan the QR code to donate
₹150 ₹500 ₹1,000 ₹2,000 ₹5,000 ₹10,000 Other