Yellow on egg shell

[McReynolds]

Have four barred rock hens not a uear old yet got 3 eggs today and a small smeer of yellow on them no sign of another egg our wet patch in coop and no evidence of preditor, what's happened?

 

[Sally PB]

Possibly a soft-shelled egg that broke. The chickens will eat the shell and the contents. You said there was no wet patch, but if they found it right away, they might have gotten the whole thing.

 

[aart]

Have four barred rock hens not a uear old yet got 3 eggs today and a small smeer of yellow on them no sign of another egg our wet patch in coop and no evidence of preditor, what's happened?

So the egg was in a nest with no mess from a broken egg?
Got a pic?