A new study has revealed that the “living dinosaur” lake sturgeon in Lake Michigan may be more than 400 years old. Lake sturgeon have been on the fossil record for 150 million years, and were already referred to as “living dinosaurs” when it was believed that their lifespan was capped at 150 years. They would then repeat this in later years, measuring the growth of the fish they had already caught. These measurements helped the researchers to estimate how long the fish had lived and what their rate of growth was. Article continues after adThe Great Lakes’ sturgeon population was nearly wiped out by fishermen in the late 1800s.