Intertemporal bone
The Intertemporal bone is a paired cranial bone present in bony fish and certain extinct amphibian-grade tetrapods. It lies in the rear part of the skull, behind the eyes.
Many lineages of four-limbed vertebrates have lost the intertemporal bone. These include Acanthostega, Icththyostega, colosteids, diadectomorphs, lepospondyls, and amniotes. Lissamphibians also lack an intertemporal. Most temnospondyls lack an intertemporal, though several early groups like edopoids, dvinosaurs, and various other basal taxa retain the bone.
Tetrapod groups which do possess an intertemporal typically have it contact the parietal bone along its inner edge, the postfrontal and postorbital bones along its front and/or outer edge, and the supratemporal bone along its rear edge. Rarely, the intertemporal may also contact the squamosal bone at a point between its contact with the postorbital and supratemporal. When the intertemporal bone is lost, either the postfrontal and supratemporal lengthen to contact each other, or the parietal widens to contact the postorbital.
