Amazing! I've never known zoos to hatch them until now.
http://www.nbcnewyork.com/news/local/Big-Headed-Turtle-Prospect-Park-Zoo-Brooklyn-236026871.html
I'm not sure what it is..All I see is that it's slime on the shell (partial yolk sack maybe?) not shell damage. They did just fine after hatching. Have no idea where they are now.
Heres a rare treat. Platysternons hatching (the only pictures around I think?). From several years back. Shared photo from Sue Teidemann.
I had contacted her a while back for breeding advice, etc.
Thought Gerard and Anthony would enjoy these too :)