Thesupratemporal bone is a pairedcranial bone present in manytetrapods andtetrapodomorphfish.[1] It is part of the temporal region (the portion of the skull roof behind the eyes), usually lying medial (inwards) relative to thesquamosal and lateral (outwards) relative to theparietal and/orpostparietal. It may also contact thepostorbital orintertemporal (which lie forwards), ortabular (which lies backwards), when those bones are present.[2]
The supratemporal is a common component of the skull in many extinctamphibians, though it is apparently absent in the lightweight skulls of livinglissamphibians (frogs and salamanders).Embryological studies ofsalamanders suggests that the supratemporal fuses with the squamosal in early development.[3] A separate supratemporal was retained by earlysynapsids andreptiles, but was strongly reduced in many groups.Squamates (lizards and snakes) still possess a small supratemporal, thougharchosaurs (crocodilians andbirds) andmammals lack it. Some extinctturtle relatives (likeProganochelys andEunotosaurus) have a prominent supratemporal, but it is absent or fused to adjacent bones in modern turtles.[4][5]
