What Really Happened to the Dinosaurs

This mural is a reference to the movie Infinity War, in which the large purple guy named Thanos obtains all the colorful infinity stones to put in his infinity gauntlet (gold glove). When he snaps his fingers while wearing the gauntlet, half the population of the universe dies by turning into dust like the dinosaur's tail. (Thanos does this because he wants to save the world from its own destruction by overpopulation, which is how his home planet was destroyed). In the movie, Spiderman says 'Mr. Stark [Ironman], I don't feel so good,' which is similar to what the dinosaur says, except Mr. Richards is the AP Biology teacher.