The T-rex ran at an average of six miles an hour also if it is hungry it is low on energy so I out run the dumb son of a bitch. Also, no way in hell am I going to that island without a AR-10 chambered for .308 and an AA12 with a drum mag full of slugs. or a M134 Minigun , the T-Rex is no match for six thousand round per minute 7.62 meat grinder. Edit: I apologize, I misinformed you. I checked and found it topped out a about 18mph, my bad. But the avereage human can run at 28mph. Also, don't forget this thing is nothing more than flesh and bone. It would have no desire to pursue me if I let it live, because my minigun can cut a Humvee in half in a matter of seconds, I just need to cut him in two, drop it and pull out the shot gun for the raptors and then pick my mini back up for the spinosaurus and walk away, Assuming this is in an open field I would have no problems. I should also mention that the spinosaurus ate mostly fish unless this is a time of drought or famine. and the Velociraptor was about two feet tall and six feet long and where not jungle hunters but rather found in desert regions.