View source for Dermal bone

{{Short description|Bony structure derived from intramembranous ossification}}
A '''dermal bone''' or '''investing bone ''' or '''membrane bone''' is a bony structure derived from [[intramembranous ossification]] forming components of the [[vertebrate]] [[skeleton]], including much of the [[skull]], [[jaw]]s, [[gill]] covers, shoulder girdle, [[fin]] rays ([[lepidotrichia]]), and the shells of [[turtle shell|turtles]] and [[armadillo#Skin|armadillos]].  In contrast to [[endochondral ossification|endochondral]] bone, dermal bone does not form from cartilage that then calcifies, and it is often ornamented.<ref name=Bu15>{{cite journal| last1=de Buffrénil |first1=V. | last2=Clarac |first2=F.| last3=Fau |first3=M.| last4=Martin | first4=S.| last5=Martin |first5=B.| last6=Pellé |first6=E.|last7=Laurin |first7=M.|year=2015 |title=Differentiation and growth of bone ornamentation in vertebrates: a comparative histological study among the Crocodylomorpha |journal=Journal of Morphology |volume=276 |issue=4 |pages=425–445 | doi=10.1002/jmor.20351|pmid=25488816 |s2cid=10809084 |doi-access=free }}</ref> Dermal bone is formed within the [[dermis]] and grows by accretion only – the outer portion of the bone is deposited by [[osteoblast]]s.

The function of some dermal bone is conserved throughout vertebrates, although there is variation in shape and in the number of bones in the [[skull roof]] and postcranial structures. In [[bony fish]], dermal bone is found in the fin [[Ray (fish fin anatomy)|rays]] and scales.  A special example of dermal bone is the [[clavicle]]. Some of the dermal bone functions regard biomechanical aspects such as protection against predators.<ref name=Ch11>{{cite journal| last1=Chen |first1=I.H. | last2=Kiang |first2=J.H.| last3=Correa |first3=V.| last4=Lopeza | first4=M.I.| last5=Chen |first5=P.Y.| last6=McKittrick |first6=J.|last7=Meyers |first7=M.A.|year=2011 |title=Armadillo armor: mechanical testing and micro-structural evaluation.|journal=Journal of Animal Ecology|volume=4|issue=5 |pages=713–722 |doi= 10.1016/j.jmbbm.2010.12.013|pmid=21565719 }}</ref><ref name=Br15>{{cite journal| last1=Broeckhoven|first1=Chris | last2=Diedericks |first2=G.| last3=Mouton |first3=P. le Fras N.| year=2015 |title=What doesn't kill you might make you stronger: functional basis for variation in body armour |journal=Journal of Animal Ecology |volume=84|issue=5 |pages=1213–1221|doi=10.1111/1365-2656.12414 | pmid=26104546|doi-access=free }}</ref><ref name=Cl19b>{{cite journal| last1=Clarac |first1=F. | last2=Goussard |first2=F.| last3=de Buffrénil |first3=V.| last4=Sansalone| first4=V.|year=2019 |title=The function(s) of bone ornamentation in the crocodylomorph osteoderms: a biomechanical model based on a finite element analysis |journal=Paleobiology |volume=45 |issue=1 |pages=182–200 | doi=10.1017/pab.2018.48|s2cid=92499041 }}</ref> The dermal bones are also argued to be involved in ecophysiological implications such as the heat transfers between the body and the surrounding environment when basking (seen in crocodilians) <ref name=Cl19>{{cite journal| last1=Clarac |first1=F. | last2= Quilhac |first2= A.|year=2019 |title= reptile The crocodylia skull and osteoderms: A functional exaptation to ectothermy?|journal=Zoology |volume=132|pages=31–40 | doi=10.1016/j.zool.2018.12.001|pmid=30736927 |s2cid=73427451 |doi-access=free }}</ref> as well as in bone respiratory acidosis buffering during prolonged apnea (seen in both crocodilians and turtles).<ref name=Ja99>{{cite journal| last1=Jackson |first1=D.C. | last2= Goldberger |first2=Z.| last3= Visuri |first3=J.| last4= Armstrong | first4=R.N.|year=1999 |title= Ionic exchanges of turtle shell in vitro and their relevance to shell function in the anoxic turtle|journal=Journal of Experimental Biology |volume=202|issue=5 |pages=503–520|doi=10.1242/jeb.202.5.513 |pmid=9929454 }}</ref><ref name=Ja03>{{cite journal| last1=Jackson |first1=DC. | last2= Andrade |first2=D.| last3= Abe |first3=AS.|year=2003 |title= Lactate sequestration by osteoderms of the broad-nose caiman, Caiman latirostris, following capture and forced submergence |journal=Journal of Experimental Biology |volume=206|issue=20 |pages=3601–3606 | doi=10.1242/jeb.00611|pmid=12966051 |doi-access=free }}</ref> These ecophysiological functions rely on the set-up of a blood vessel network within and straight above the dermal bones. <ref name=Cl18>{{cite journal| last1=Clarac |first1=F. | last2= de Buffrénil |first2=V.| last3= Cubo|first3=J.| last4=Quilhac| first4=A.|year=2018 |title= Vascularization in ornamentedosteoderms: physiological implications in ectothermy and amphibious lifestyle in the crocodylomorphs? |journal=Anatomical Record |volume=301|issue=1 |pages=175–183 | doi=10.1002/ar.23695|pmid=29024422 |doi-access=free}}</ref>

==References==
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{{DEFAULTSORT:Dermal Bone}}
[[Category:Vertebrate anatomy]]
[[Category:Dermal and subcutaneous growths]]
[[Category:Armour (zoology)]]

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