Coneheads are normal for newborns.
However, flattening of the back of the head is not. This is often caused by babies being on their back as the preferred position. To prevent this, each baby should stay on their stomachs for between 30 to 60 minutes a day
collectively ar about 5 - 10 minutes an hour until the desired time is met. This should be statred as early as possible after birth.