Thearticular boneis part of the lower jaw of mostvertebrates,including mostjawed fish,amphibians,birdsand various kinds ofreptiles,as well as ancestralmammals.

Mammalian and non-mammalian jaws. In the mammal configuration, thequadrateandarticularbones are much smaller and form part of the middle ear. Note that in mammals the lower jaw consists of only thedentarybone.

Anatomy

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In most vertebrates, the articular bone is connected to two other lower jaw bones, thesuprangularand theangular.[1]Developmentally, it originates from the embryonic mandibular cartilage. The mostcaudalportion of the mandibular cartilage ossifies to form the articular bone, while the remainder of the mandibular cartilage either remains cartilaginous or disappears.[1]

In snakes

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Insnakes,the articular, surangular, and prearticular bones have fused to form the compound bone. The mandible is suspended from the quadrate bone and articulates at this compound bone.[2]

Function

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In amphibians and reptiles

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In most tetrapods, the articular bone forms the lower portion of the jaw joint. The upper jaw articulates at thequadrate bone.[3]

In mammals

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Inmammals,the articular bone evolves to form themalleus,one of the mammalianossiclesof the middle ear. This is anapomorphyof the mammalian clade,[4]and is used to determine the fossil transition to mammals.[5]It isanalogousto, but nothomologousto thearticular processof thelower jaw.

After the loss of the quadrate-articular joint, the squamosal and dentary bones form the new jaw joint in mammals.[6]

See also

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References

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  1. ^abHomberger, Dominique G. (2004).Vertebrate dissection.Walker, Warren F. (Warren Franklin), Walker, Warren F. (Warren Franklin). (9th ed.). Belmont, CA: Thomson Brooks/Cole.ISBN0-03-022522-1.OCLC53074665.
  2. ^Kardong, Kenneth V. (2012).Vertebrates: comparative anatomy, function, evolution(6th ed.). New York: McGraw-Hill.ISBN978-0-07-352423-8.OCLC664665896.
  3. ^"University of the Cumberlands, QUADRATE AND ARTICULAR EXPRESSION".Archived fromthe originalon 2017-05-17.Retrieved2016-07-16.
  4. ^"Mammaliformes: Overview - Palaeos".Archived fromthe originalon 2007-04-29.
  5. ^Kardong, Kenneth V. (2012).Vertebrates: comparative anatomy, function, evolution(6th ed.). New York: McGraw-Hill.ISBN978-0-07-352423-8.OCLC664665896.
  6. ^Kermack, D. M. (1984).The evolution of mammalian characters.Kermack, K. A. London: Croom Helm.ISBN0-7099-1534-9.OCLC10710687.