Articular bone
Thearticular boneis part of the lower jaw of mostvertebrates,including mostjawed fish,amphibians,birdsand various kinds ofreptiles,as well as ancestralmammals.
Anatomy
[edit]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
[edit]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
[edit]In amphibians and reptiles
[edit]In most tetrapods, the articular bone forms the lower portion of the jaw joint. The upper jaw articulates at thequadrate bone.[3]
In mammals
[edit]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
[edit]References
[edit]- ^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.
- ^Kardong, Kenneth V. (2012).Vertebrates: comparative anatomy, function, evolution(6th ed.). New York: McGraw-Hill.ISBN978-0-07-352423-8.OCLC664665896.
- ^"University of the Cumberlands, QUADRATE AND ARTICULAR EXPRESSION".Archived fromthe originalon 2017-05-17.Retrieved2016-07-16.
- ^"Mammaliformes: Overview - Palaeos".Archived fromthe originalon 2007-04-29.
- ^Kardong, Kenneth V. (2012).Vertebrates: comparative anatomy, function, evolution(6th ed.). New York: McGraw-Hill.ISBN978-0-07-352423-8.OCLC664665896.
- ^Kermack, D. M. (1984).The evolution of mammalian characters.Kermack, K. A. London: Croom Helm.ISBN0-7099-1534-9.OCLC10710687.