Odd mass inside egg looks like developing chick - but I have no roosters...?

[ZCS2014]

This is the first time I have seen this in my flock and was surprised to see it. I did search first here and I did find a post with something similar. It was determined in that post to be a fertilized egg starting to form as the other person has a rooster.

I don't have one. My whole flock of 6 are females and all are laying. I know who lays what shape & color egg because each one is a different breed and purchased in different years. How can this happen if I don't have a rooster? Or is this not a developing chick? It looks like it to me based on google images i found and the "umbilical cord"-looking part that connected to the yolk.

 

[sourland]

Do an on site search on 'lash egg'. That appears to be either a lash egg or large meat spot included inside the egg. It is not a developing chick. This tends to happen more frequently in aging birds and may be a one time deal or may become a chronic condition.