Answer:
By observing the size of fontanels.
Step-by-step explanation:
The archaeologist can determine the age of the skull bones found by observing the fact that whether the large bones of the cranium are fused or not.
The large bones of the skull are joined by connective tissues which is known as fontanels.
The archaeologist can estimate the time it takes for the fontanels to close and this can be determined by observing the size of the fontanels.
Therefore, the observation of the size of the fontanels provides a good estimate of the age of the child which is predicted to be less than 1 year old.