Fairy eggs with only yolks no whites

[Edens_Echo]

We've got a nice little flock of 20 mixed breed chickens that have the same father and 2 different mothers, the older brood is now a year old and been doing very well. Started laying at about 24 weeks. The younger brood just recently started laying about 6 - 8 weeks ago and I seem to have 3-4 hens in this lot that are consistently laying fairy eggs that have almost zero white in them and are all yolk. Bigger yolks than the usual medium sized eggs even. I thought perhaps this was a new layer glitch but now I'm getting more interested in what is going on as they are very consistent and always have large yolks. We do eat them (yolks are my favourite so I'm ok if this is just what they're going to do), but I'm curious...Anyone with any thoughts for me please?

 

[aart]

that are consistently laying fairy eggs that have almost zero white in them and are all yolk.

Generally 'fairy' eggs have no, or tiny, yolks.

Bigger yolks than the usual medium sized eggs even.

Pics don't really show size, take pics with a quarter for scale...
...and open the small eggs to see just what's inside.

 

[Perris]

One of mine laid such an egg 2 days ago; this one also had a very thin shell. Only seen those with white and no yolk hitherto. But such a thing can happen: weighed 25g

And the yolk wasn't normal when opened; two meat spots and some thick albumen inside the membrane

I don't know who laid it. One of the pullets I assume.