Book 32, Question 24
How do bones tell scientists how old a reptile was?
Bones grow a little each year, and the growth slows in cold or dry seasons.
Scientists can slice a tiny piece of bone, such as one from a toe or limb, and see thin lines where growth paused. Counting the lines gives a good guess of the animal’s age. It works much like counting tree rings. This helps researchers learn how long reptiles live.