This beardie hatched today and was having trouble getting out of the egg. After removing him I could see why. He is severely deformed. It's spine just above the tail bends straight back towards its head. Its abdominal cavity is also fully exposed. Amazingly it was the first to pip.
The siblings all appear normal. The parents were also not siblings. Incubation temps were very steady. I think it was just a fluke congenital defect. It was obvious he would not live so he was humanely put to rest.