Editing Skeleton (section)

====Marine mammals====
[[File:Zalophus californianus 01.JPG|thumb|left|[[Californian sea lion]]]]
To facilitate the movement of [[marine mammal]]s in water, the hind legs were either lost altogether, as in the whales and [[manatee]]s, or united in a single [[fish fin|tail fin]] as in the [[pinnipeds]] (seals). In the whale, the [[cervical vertebrae]] are typically fused, an adaptation trading flexibility for stability during swimming.<ref>{{cite journal |last1=Bebej |first1=Ryan M |last2=Smith |first2=Kathlyn M |title=Lumbar mobility in archaeocetes (Mammalia: Cetacea) and the evolution of aquatic locomotion in the earliest whales |journal=Zoological Journal of the Linnean Society |date=17 March 2018 |volume=182 |issue=3 |pages=695–721 |doi=10.1093/zoolinnean/zlx058 |url=https://academic.oup.com/zoolinnean/article/182/3/695/4554339?login=true |access-date=7 March 2022 |issn=0024-4082}}</ref>