Dr. Lewis is much like Knight Rider and/or
Batman. He has many gadgets to get him around. One being the Dodge Viper GTS Coupe. Which spits fire. On to the giant Brachiosaurus. Dr. Dave also used his great ability in Inorganic Chemistry to sway the giant dinosaur to imbibe a toxic chemical which emitted a foul toxin only to drown and poison the creature to utter extinction. After the tragedy, dinosaurs could not come within 1700 yards of the toxin without falling to their death. He didn't even need to use the machine gun. Way to go, Dr. Dave.