Looks like corrugated shell... crack it open and check for double yolk! I'd eat it
"This happens when the egg membrane is thinner than it should be, often as a result of double ovulation (two yolks) and having to stretch thinner to cover the extra egg contents. This results in insufficient plumping of the egg, leaving a corrugated membrane onto which the shell gets deposited, so the shell takes on a corrugated appearance as well. Causes are:
- Extra large egg size, often double or multi yolk eggs;
- Newcastle disease;
- Excessive use of antibiotics;
- Copper deficiency in the hen's diet;
- Excess calcium consumption;
- A defective shell gland;
- It is often seen with hens recovering from infectious bronchitis;
- It can be hereditary.