Honest question - what has stopped us from bringing extinct dinosaurs back to life? Which variable in the equation is unsolved?
See eg https://www.nhm.ac.uk/discover/could-scientists-bring-dinosa...
As an aside though, wasn't there a place to reintroduce wooly mammoths? Wonder what happened to that.
The oldest DNA sample is estimated to be 800,000 years old.
So we simply don't have DNA from a dinosaur.
https://www.ted.com/talks/jack_horner_building_a_dinosaur_fr...