Original: In The Valley of Gwangi , Gwangi is billed as an Allosaurus , although Ray Harryhausen based his model for the creature on Charles R. Knight 's depiction of a Tyrannosaurus .
Simplified: Gwangi is billed as an Allosaurus , though Ray Harryhausen based his model for the creature on Charles R. Knight 's depiction of a Tyrannosaurus .