Once you have cured one of your diseased animals, buy a lab. Click it then click "Find Fossils". You will see an "X" mark on your right. It is at the middle right. After you click it, you will have a Fossil Detector. The fossil detector also can be upgraded by digging upgrades or by getting more fame for the zoo. Once you get all the fossils, go back to the lab and click "Build Fossil". Once you put it back, click "Build Extinct Animal". You will see keyboard keys. Press them once the green line is touching them. Once you get them all correct, your score will be 100% and you will have a super dinosaur.