Today this egg was laid by a young chicken that usually lays normal looking eggs, and has not produced anything strange. She has access to oyster shell, grit, the normal feed and scratch, and she free ranges for several hours every day. She seems perfectly normal with no other strange symptoms. This egg had four or five leathery layers and was quite large. There was a normal sized egg inside all of it. The inside of it looked typical. Has anyone had this before? I am wondering what causes it? I have done research and all I see is that possibly the egg was pushed back inside so formed another shell. But this had four or five. Any comments or experiences are greatly appreciated! Thank you! 
