I have my own take on this. But it may be just me. Some people are actually born naturally this way. My son was. I was told to place him in a helmet for 23 hrs a day, 7 days a week, and I did, he wore the helmet until he was 15 months old. Some people are born with or develop this shape. Either cause is plagaciphaly, a defect of the child being on one side on head too long while lying on back can cause this or the latter, fibrous dysplasia of the bone. Initially affecting the skull as well as long bones such as arms and legs. The latter cause is the bone being replaced by fibrous soft cartilage causing weaker bones and the calcite deposits into the blood stream from the disolvment of bone. This in turn causes not only the deformity of the skull but also kidney stones, bone pain, hyperplasia and lymphademia ( over producing white blood cells and lymph nodes are too full) resulting in high fevers, fever seizures, and swelling of organs due to white blood cells attaching onto organs due to no other place to go. Eventually the bones harden, the elongation of the skull and other affected bones stop as well as pain,fevers, etc.
My son was born with the latter.
As I believe the originals that ruled had these elongated skulls. It can be passed down generation to generation. Not sure how far it can travel.
But then again, the world is full of strange and mysterious things that go bump in the night…😉 or is it?