Outlaws Vs Tyrannosaur

Anyone remember The Valley of Gwangi, the classic cowboys vs. dinosaurs movie featuring the work of stop-motion animation genius Ray Harryhausen?

Our Old-West/Prehistoric Creature mashup has a somewhat different story line. In our tabletop tale, three outlaws try to ambush a T-Rex, using one of their gang members as bait. Any wagers as who prevails, ambitious gunmen or terrible lizard?