external pip, internal zip

[lilstar]

Has anyone ever seen this? This is at my daughter's preschool hatch. Several ducklings made it out of their eggs yesterday and are now fluffy and adorable in the brooder. There's one duckling in the incubator still, a couple unpipped eggs, and then this one, pic below. The picture shows one pip, then you can see a darker line where it looks like the membrane has been zipped but not the shell! At the other end, just out of view of the camera, is another pip. It looks like 2 external pips on opposite ends of an internal zip.