Not sure if I ever mentioned this before to you. I know guy that used to be a commercial collector in NV. He sware he thought that chuckwalla eggs could over-winter and hatch in the spring. SO one year I tried an experiment. I got a clutch of eggs and kept the at the normal 30C for a month then gradually over a period of a month dropped them to about 18C. The darn things hatched after about 75 days at 16-20C. I could not believe it. So they were in the incubator or should I say nest box for over 4 months total. If I remember correct I think all but one had twisted and or kinked tails. Sometimes I think these eggs are tougher than we give them credit for!