Editing Temporal bone (section)

== Other animals ==
In many animals some of these parts stay separate through life:
* [[Squamosal]]: the squama including the zygomatic process
* [[Tympanic bone]]: the tympanic part: this is derived from the [[angular bone]] of the reptilian lower jaw
* [[Periotic bone]]: the petrous and mastoid parts
* Two parts of the [[hyoid]] arch: the styloid process. In the dog these small bones are called [[tympanohyal]] (upper) and [[stylohyal]] (lower).

In evolutionary terms, the temporal bone is derived from the fusion of many bones that are often separate in non-human mammals:
* The [[squamosal]] bone, which is [[homology (biology)|homologous]] with the squama, and forms the side of the cranium in many [[Osteichthyes|bony fish]] and [[tetrapod]]s. Primitively, it is a flattened plate-like bone, but in many animals it is narrower in form, for example, where it forms the boundary between the two [[temporal fenestra]]e of [[diapsid]] reptiles.<ref name=VB>{{cite book |author=Romer, Alfred Sherwood|author2=Parsons, Thomas S.|year=1977 |title=The Vertebrate Body |publisher=Holt-Saunders International |location= Colorado, PA|pages= XXX|isbn= 0-03-910284-X}}</ref>
* The petrous and mastoid parts of the temporal bone, which derive from the [[periotic bone]], formed from the fusion of a number of bones surrounding the ear of reptiles. The delicate structure of the [[middle ear]], unique to mammals, is generally not protected in [[marsupial]]s, but in [[placental mammal|placental]]s, it is usually enclosed within a bony sheath called the [[auditory bulla]]. In many mammals this is a separate '''tympanic bone''' derived from the [[angular bone]] of the reptilian lower jaw, and, in some cases, it has an additional '''entotympanic bone'''. The auditory bulla is homologous with the tympanic part of the temporal bone.<ref name=VB/>
* Two parts of the [[hyoid]] arch: the styloid process. In the dog the styloid process is represented by a series of four articulating bones, from top down [[tympanohyal]], [[stylohyal]], [[epihyal]], [[ceratohyal]]; the first two represent the styloid process, and the ceratohyal represents the anterior horns of the [[hyoid bone]] and articulates with the [[basihyal]] which represents the body of the hyoid bone.