Final answer:
The greater or anterior fontanelle is a diamond-shaped soft spot located at the top front of a newborn's skull. It allows the bony plates of the skull to move during birth and gradually closes as the bones of the skull ossify.
Step-by-step explanation:
The greater or anterior fontanelle is a diamond-shaped soft spot located at the top front of a newborn's skull. It is the largest fontanelle and is formed by connective tissue between the frontal and parietal bones. The fontanelle allows the bony plates of the skull to move and change shape during birth and enables the baby's head to pass through the birth canal.
The size of the fontanelle varies, but in general, it is around 2 to 3 cm wide. It is usually described as feeling like a firm, slightly depressed area on the baby's head. The fontanelle gradually closes as the bones of the skull ossify, with the greater fontanelle closing by nine to 18 months after birth.