Someone asked the fellow behind What-If.xkcd how much real dinosaur is in a plastic dinosaur.
The thought behind the question is that plastic is made from chemicals that use petroleum and other hyrdrocarbons as a base. Those chemicals themselves are supposed to be the remains of dead dinosaurs, compressed and acted upon by millions of years of geologic and biological processes to become the stuff we pump from the ground and process into what makes cars go.
Except, as the answer man points out, most of the original critters that make up crude oil and natural gas weren't dinosaurs. So the plastic that makes a toy dinosaur probably doesn't have nearly as much dinosaur leftover as you or I do.