Things can be a little slow in the life of a Tuatara. From mating to fertilisation of the egg can take 3 years. From there a further 11-16 months can pass before the eggs hatch. Tuatara are not sexually mature until the age of around 10 but they can continue reproducing for over 50 years. They grow slowly and can take 35 years before reaching their full size, oh, and they can hold their breath for an hour-see page 118 and laugh at how Tipi was trying to do the same.