While working at an excavation, an archaeologist finds several small skull bones. She examines the frontal, parietal, and occipital bones and concludes that the skulls are those of children not yet 1 year old. How can she tell their ages from an examination of these bones?

By observing the size of fontanels.

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.