Editing Shark (section)

===Skeleton===
Shark skeletons are very different from those of [[Osteichthyes|bony fish]] and [[tetrapod|terrestrial vertebrates]]. Sharks and other [[chondrichthyes|cartilaginous fish]] ([[Skate (fish)|skate]]s and [[batoidea|rays]]) have skeletons made of [[cartilage]] and [[connective tissue]]. Cartilage is flexible and durable, yet is about half the normal density of bone. This reduces the skeleton's weight, saving energy.<ref name="skeletoncorset">{{cite web
|url=http://www.elasmo-research.org/education/white_shark/skeleton.htm
|title=Skeleton in the Corset
|last=Martin
|first=R. Aidan
|publisher=ReefQuest Centre for Shark Research
|access-date=2009-08-21
|archive-url=https://web.archive.org/web/20091125073318/http://www.elasmo-research.org/education/white_shark/skeleton.htm
|archive-date=2009-11-25
|url-status=live
}}</ref> Because sharks do not have rib cages, they can easily be crushed under their own weight on land.<ref name=langoni>{{cite web|archive-url=https://web.archive.org/web/20100805003021/http://langonigraphix.com/skeleton.html|archive-date=August 5, 2010 |url=http://langonigraphix.com/skeleton.html
|title=A Shark's Skeleton & Organs
|access-date=August 14, 2009
}}</ref>