One degree here or there makes ALL the difference. But it's not even just one degree we're talking about here. 99.5 is two full degrees lower than it should be for a still air bator, and that's IF the measurement's coming from the tops of the eggs. If the thermometer has been at a different height, the temps at the centre of the eggs could have been as much as 3 or 4 degrees off. Which means that they could still be viable, but just VERY late due to the low temps.
Being very optimistic, I would say that the one you opened could possibly have died cause it just wasn't fully developed yet. if I were you, I think I'd leave the others in for another day anyway. I mean, what have you got to lose at this point? I don't think they'll all hatch out healthy on day 26, nothing like it. But if you're lucky you might get a few pipping the shells, and you might have to assist them to hatch...
Anyway, I'd say the problem was definitely your temps, not the shipped eggs or your humidity or anything else. Shipped eggs ARE a gamble, but if you've opened two eggs and found fully developed chicks, the shipping obviously wasn't all that rough on the eggs. Shipping trauma usually causes eggs to either not develop at all or to die in the first week. If they make it as far as lockdown then die, it's very unlikely that it's the shipping that's to blame.
Don't give up - figure out what went wrong and sort it for the next hatch. Sooner or later you'll get it figured out...
Being very optimistic, I would say that the one you opened could possibly have died cause it just wasn't fully developed yet. if I were you, I think I'd leave the others in for another day anyway. I mean, what have you got to lose at this point? I don't think they'll all hatch out healthy on day 26, nothing like it. But if you're lucky you might get a few pipping the shells, and you might have to assist them to hatch...
Anyway, I'd say the problem was definitely your temps, not the shipped eggs or your humidity or anything else. Shipped eggs ARE a gamble, but if you've opened two eggs and found fully developed chicks, the shipping obviously wasn't all that rough on the eggs. Shipping trauma usually causes eggs to either not develop at all or to die in the first week. If they make it as far as lockdown then die, it's very unlikely that it's the shipping that's to blame.
Don't give up - figure out what went wrong and sort it for the next hatch. Sooner or later you'll get it figured out...