In 2003 samples of the Starchild Skull's bone were examined using a scanning electron microscope at the Royal Holloway University in London. Previous research had discovered that the bone was thinner, lighter, and harder to cut than normal human bone, and it was hoped that this investigation would help to explain why.

When the bone sample was examined under magnification, strange fibers were visible on the cut surface, apparently emerging from inside the bone. Mycologists were informally consulted in an attempt to identify them as a fungus or other organism. They said that it did not look like a biological contamination. To the best of our knowledge, nothing like this has ever been seen in any other kind of bone.

Speculation is that these fibers act like the steel reinforcing rods in concrete, but so far the Starchild Project has not been able to isolate the fibers for further testing.  An unclassified medical condition called "Morgellons Disease" has been suggested as the cause of the fibers, but the size, shape, and appearance of the fibers in the Starchild bone are completely unlike those linked to Morgellons.

The images below are duplicates of the original photographs taken by the microscope.