"Decapitated body" makes sense. But we mostly consider the head when talking about people (mugshots are heads, etc) -- so why aren't people decorporated rather than decapitated? Lavoisier's blinking experiment after his beheading didn't involve picking up his body!
(yes, yes I know that that is why this planaria experiment is so interesting).
If you don't know about Lavoisier's alleged extreme science experiment: http://www.strangehistory.net/2011/02/06/lavoisier-blinks/