Squamosal bone
The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone.[1]
In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull.[2] The bone forms an ancestral component of the dermal roof and is typically thin compared to other skull bones.[3]
The squamosal bone lies
Function in reptiles
In reptiles, the quadrate and articular bones of the skull articulate to form the jaw joint. The squamosal bone lies anterior to the quadrate bone.[3]
Anatomy in synapsids
Non-mammalian synapsids
In non-mammalian
Mammals
In many mammals, including humans, the squamosal fuses with the
In mammals, the quadrate bone evolves to form the incus, one of the ossicles of the mammalian ear.[5] Similarly, the articular bone evolves to form the malleus. The squamosal bone migrates and lengthens to become a new point of articulation with the lower jaw (at the dentary bone).[3]
References
- S2CID 85000711.
- )
- ^ OCLC 53074665.
- ^ Roemer, A. S. (1956). Osteology of the Reptiles. University of Chicago Press. p. 772.
- ^ Carr, Steven M. (2005). "Quadroarticular vs Dentary-Squamosal jaw". Memorial University of Newfoundland. Retrieved 2018-04-09.
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