Tusks are elongated, continuously growing front teeth that protrude well beyond the mouth of certain mammal species. They are most commonly canine teeth, as with narwhals, musk deer, pigs, hippopotamuses and walruses, or, in the case of elephants, elongated incisors. Tusks share common features such as extra-oral position, growth pattern, composition and structure, and lack of contribution to ingestion. Tusks are thought to have adapted to the extra-oral environments, like dry or aquatic or arctic.[1] In most tusked species both the males and the females have tusks although the males' are larger. Most mammals with tusks have a pair of them growing out from either side of the mouth. Tusks are generally curved and have a smooth, continuous surface. The male narwhal's straight single helical tusk, which usually grows out from the left of the mouth, is an exception to the typical features of tusks described above. Continuous growth of tusks is enabled by formative tissues in the apical openings of the roots of the teeth.[2][3] Prior to over hunting and proliferation of the ivory trade, elephant tusks weighing over 90 kg (200 lb) were not uncommon, though it is rare today to see any over 45 kg (100 lb).[4]

An African elephant in Tanzania, with visible tusks

Other than mammals, dicynodonts are the only known vertebrates to have true tusks.[5]

Function Edit

Tusks have a variety of uses depending on the animal. Social displays of dominance, particularly among males, are common, as is their use in defense against attackers. Elephants use their tusks as digging and boring tools. Walruses use their tusks to grip and haul out on ice.[6] It has been suggested that tusk's structure has evolved to be compatible with extra-oral environments.[1]

Use by humans Edit

Tusks are used by humans to produce ivory, which is used in artifacts and jewellery, and formerly in other items such as piano keys. Consequently, many tusk-bearing species have been hunted commercially and several are endangered. The ivory trade has been severely restricted by the United Nations Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

Tusked animals in human care may undergo tusk trimming or removal for health and safety concerns.[7] Furthermore, surgical veterinary procedures to remove tusks have been explored to mitigate human-wildlife conflicts.[8]

Gallery Edit

See also Edit

References Edit

  1. ^ a b Nasoori, Alireza (2020). "Tusks, the extra-oral teeth". Archives of Oral Biology. 117: 104835. doi:10.1016/j.archoralbio.2020.104835. PMID 32668361. S2CID 220585014.
  2. ^ "Tusk". The Oxford English Dictionary. 2010.
  3. ^ Konjević, Dean; Kierdorf, Uwe; Manojlović, Luka; Severin, Krešimir; Janicki, Zdravko; Slavica, Alen; Reindl, Branimir; Pivac, Igor (4 April 2006). "The spectrum of tusk pathology in wild boar (Sus scrofa L.) from Croatia" (PDF). Veterinarski Arhiv. 76 (suppl.) (S91–S100). Retrieved 9 January 2011.
  4. ^ "Still Life" by Bryan Christy. National Geographic Magazine, August, 2015, pp. 97, 104.
  5. ^ Whitney, M. R.; Angielczyk, K. D.; Peecook, B. R.; Sidor, C. A. (2021). "The evolution of the synapsid tusk: Insights from dicynodont therapsid tusk histology". Proceedings of the Royal Society B: Biological Sciences. 288 (1961). doi:10.1098/rspb.2021.1670. PMC 8548784. PMID 34702071.
  6. ^ Fay, F.H. (1985). "Odobenus rosmarus". Mammalian Species (238): 1–7. doi:10.2307/3503810. JSTOR 3503810. Archived from the original on 2013-09-15. Retrieved 2009-01-22.
  7. ^ Rose, Josephine B.; Leeds, Austin; LeMont, Rachel; Yang, Linda M.; Fayette, Melissa A.; Proudfoot, Jeffry S.; Bowman, Michelle R.; Woody, Allison; Oosterhuis, James; Fagan, David A. (2022-03-03). "Epidemiology of Traumatic Tusk Fractures of Managed Elephants in North America, South America, Europe, Asia and Australia". Journal of Zoological and Botanical Gardens. 3 (1): 89–101. doi:10.3390/jzbg3010008. ISSN 2673-5636.
  8. ^ Mutinda, Matthew; Chenge, Geoffrey; Gakuya, Francis; Otiende, Moses; Omondi, Patrick; Kasiki, Samuel; Soriguer, Ramón C.; Alasaad, Samer (2014-03-10). Sueur, Cédric (ed.). "Detusking Fence-Breaker Elephants as an Approach in Human-Elephant Conflict Mitigation". PLOS ONE. 9 (3): e91749. Bibcode:2014PLoSO...991749M. doi:10.1371/journal.pone.0091749. ISSN 1932-6203. PMC 3948880. PMID 24614538.