Life Preservers Tips and Tricks Include: To give teachers flexibility when they use Life Preservers in their classroom, MSU created a long and a short version of the game. The short version has only one round, THE AGE OF DINOSAURS. It takes about 30 minutes to play. The long version has that same identical round and then continues to THE AGE OF MAMMALS. The long version takes about 45 minutes to play.

Modified from Source