Found egg without shell? Help Please?

[feather and mountain man]

I found an egg laying on the ground this morning without a shell. It has white, yolk, and skin but no shell. It was frozen by the time I found it. I want to know why this happened and how do I know whick chicken did this. I have layer mix from local feed store. It has all nutrients needed and oyster shells. So please help me to understand and tell me what I need to do.

 

[Ivywoods]

My brother in law says the roosters lay those eggs without a shell.

What's worse is he totally believed his idea.

Seriously, I have seen this, too, but I have no idea what the itiology is. I know when it happened, it never has been a recurring problem for me. I'm sure someone with more chicken savvy will chime in here.