Pipped but didnt zip

[Cod Lennen]

Just curious if this has happened to anyone else. I have hatched a lot of eggs and have never had this happen. I just finished a hatch of chicks. My last egg had a pip and had started to zip. The membrane had discolored and everything else had hatched. I peeled the shell back slowly along with the membrane. The veins had receded and the rest of the membrane had a good color. The problem was I couldn't find the beak and could tell it was dead in egg. I proceeded to unzip the egg and found the chicks beak on the other side of the egg. It had turned half way around the egg without unzipping. It looked developmentally OK. Just curious if anyone would know why this happened.

 

[Rose Quartz]

Just curious if this has happened to anyone else. I have hatched a lot of eggs and have never had this happen. I just finished a hatch of chicks. My last egg had a pip and had started to zip. The membrane had discolored and everything else had hatched. I peeled the shell back slowly along with the membrane. The veins had receded and the rest of the membrane had a good color. The problem was I couldn't find the beak and could tell it was dead in egg. I proceeded to unzip the egg and found the chicks beak on the other side of the egg. It had turned half way around the egg without unzipping. It looked developmentally OK. Just curious if anyone would know why this happened.

Weird. Was the egg thicker on that side? I can't imagine why it would stop twitching it's head to break the shell.

 

[Cod Lennen]

The shell looked and felt completely normal.