You are correct that annuli do not tell the exact age of the turtle but they are used to estimate age, as the video states. It certainly takes a trained eye to tell the difference between an annual growth ring and a false growth ring but nonetheless, is one of the few ways we have to estimate age structure within a population. Age estimation using annuli is pretty accurate at least until sexual maturity. The proper term for scute growth rings is annuli.
Box turtles commonly live 25-30 years in the wild but have been known to reach ages of 40-50 years old. There are records of box turtles living more than 100 years but this is probably rare.
This video gives the impression that a ring on a scute equals a year of growth. By calling them "annuli" you further give the impression that one of these rings represents a year - to be clear these "annuli" each represent a growth spurt and it is normal to produce severa in one year based on the abundance and variety of food as well as climatic conditions. Under normal conditions there is never only one ring produced in a year until maximum size is reached. Age by counting rings isn't accurate!
