Editing Skeleton (section)

===Endoskeletons===
{{Main article|Endoskeleton}}
[[Image:Eptesicus fuscus skeleton.jpg|thumb|[[Endoskeleton]] of a [[bat]]]]

Endoskeletons are the internal support structure of an animal, composed of [[mineralized tissues]], such as the bone skeletons found in most vertebrates.<ref name="de Buffrénil et al. 2021">{{cite book |last1=de Buffrénil |first1=Vivian |last2=de Ricqlès |first2=Armand J |last3=Zylberberg |first3=Louise |last4=Padian |first4=Kevin |last5=Laurin |first5=Michel |last6=Quilhac |first6=Alexandra |title=Vertebrate skeletal histology and paleohistology |date=2021 |publisher=CRC Press |location=Boca Raton, FL |isbn=978-1351189576 |pages=xii + 825|url=https://books.google.com/books?id=tJcwEAAAQBAJ&dq=Vertebrate+Skeletal+Histology+and+Paleohistology&pg=PT8}}</ref> Endoskeletons are highly specialized and vary significantly between animals.<ref name="National Geographic-2021" /> They vary in complexity from functioning purely for support (as in the case of [[Porifera|sponges]]), to serving as an attachment site for muscles and a mechanism for transmitting muscular forces. A true endoskeleton is derived from [[germ layer#Mesoderm|mesodermal]] tissue. Endoskeletons occur in [[chordate]]s, echinoderms, and sponges.