[[File:Petrolacosaurus skull diagram.png|thumb|Skull of ''Petrolacosaurus'', showing supratemporal on upper right]] The '''supratemporal bone''' is a paired cranial bone present in many tetrapods and tetrapodomorph fish.<ref>{{Cite journal |last1=Qiao |first1=Tuo |last2=Zhu |first2=Min |date=2010 |title=Cranial morphology of the Silurian sarcopterygian Guiyu oneiros (Gnathostomata: Osteichthyes) |url=http://link.springer.com/10.1007/s11430-010-4089-6 |journal=Science China Earth Sciences |language=en |volume=53 |issue=12 |pages=1836–1848 |doi=10.1007/s11430-010-4089-6 |bibcode=2010ScChD..53.1836Q |s2cid=54963054 |issn=1674-7313|url-access=subscription }}</ref> It is part of the temporal region (the portion of the skull roof behind the eyes), usually lying medial (inwards) relative to the squamosal and lateral (outwards) relative to the parietal and/or postparietal. It may also contact the postorbital or intertemporal (which lie forwards), or tabular (which lies backwards), when those bones are present.<ref>{{Cite journal |last=Parrington |first=F.R. |date=1937 |title=V.— A note on the supratemporal and tabular bones in reptiles |url=https://www.tandfonline.com/doi/full/10.1080/00222933708655315 |journal=Annals and Magazine of Natural History |language=en |volume=20 |issue=115 |pages=69–76 |doi=10.1080/00222933708655315 |issn=0374-5481|url-access=subscription }}</ref>
The supratemporal is a common component of the skull in many extinct amphibians, though it is apparently absent in the lightweight skulls of living lissamphibians (frogs and salamanders). Embryological studies of salamanders suggests that the supratemporal fuses with the squamosal in early development.<ref>{{Cite journal |last=Schoch |first=Rainer R. |date=2014 |title=Amphibian skull evolution: The developmental and functional context of simplification, bone loss and heterotopy |url=https://onlinelibrary.wiley.com/doi/10.1002/jez.b.22599 |journal=Journal of Experimental Zoology Part B: Molecular and Developmental Evolution |language=en |volume=322 |issue=8 |pages=619–630 |doi=10.1002/jez.b.22599|bibcode=2014JEZB..322..619S |url-access=subscription }}</ref> A separate supratemporal was retained by early synapsids and reptiles, but was strongly reduced in many groups. Squamates (lizards and snakes) still possess a small supratemporal, though archosaurs (crocodilians and birds) and mammals lack it. Some extinct turtle relatives (like ''Proganochelys'') have a prominent supratemporal, but it is absent or fused to adjacent bones in modern turtles.<ref>{{Cite journal |last1=Gaffney |first1=Eugene S. |last2=Meeker |first2=Lorraine J. |date=1983-03-01 |title=Skull morphology of the oldest turtles: a preliminary description of Proganochelys quenstedti |url=https://doi.org/10.1080/02724634.1983.10011953 |journal=Journal of Vertebrate Paleontology |volume=3 |issue=1 |pages=25–28 |doi=10.1080/02724634.1983.10011953 |bibcode=1983JVPal...3...25G |issn=0272-4634|url-access=subscription }}</ref><ref>{{Cite journal |last1=Bever |first1=G. S. |last2=Lyson |first2=Tyler R. |last3=Field |first3=Daniel J. |last4=Bhullar |first4=Bhart-Anjan S. |date=2015 |title=Evolutionary origin of the turtle skull |url=https://www.researchgate.net/publication/281541882 |journal=Nature |language=en |volume=525 |issue=7568 |pages=239–242 |doi=10.1038/nature14900 |bibcode=2015Natur.525..239B |s2cid=4401555 |issn=1476-4687}}</ref>
== References == {{reflist}} {{Tetrapod osteology|S.}}
Category:Fish anatomy Category:Amphibian anatomy Category:Reptile anatomy Category:Skull bones {{anatomy-stub}}