Wrinkly Egg Shape - What’s Up?

[Polson]

I have been raising chickens for years and have had all sorts of breeds. I have seen all sorts of egg shapes (soft & hard) even creased, but this one takes the cake. This hen has laid hundreds of normal eggs until this one. The last few have had some minor wrinkles on the end but it’s barely noticeable. This last one is very wrinkly with a hard shell....not soft. She is only 2 years old. Anyone have an idea what’s up?

 

[sumi]

There are a number of possible causes for this. See #13 here: https://www.backyardchickens.com/articles/common-egg-quality-problems.65923/

 

[MountainChook]

I have had several of these egg this winter too. I don't know which hen laid them as I have 20 and they lay in each others nests, I can't tell you why but it's a first for me too.