Did Raptorex Really Exist?

Paleontologists have been studying and drawing totally different conclusions about the fossil LH PV18 for almost a decade. Is it just one of many specimens of a theropod called Tarbosaurus bataar or is it an entirely different theropod named Raptorex kriegsteini? In order to answer this question, you have to understand the many ways in which we can--and can't--determine the age of a fossil.