It was also severely neurologically impaired, so much so that it was doomed from the start. It likely only lived as long as it did because it was a chimeric paradox, the result of fraternal twins fusing early in development. In this case a normal and a super jag. Its almost certain that the normal tissue from the normal twin particularly in the area of the lung allowed to live for a short time. Normal super-jags hatch with an underdeveloped and often collapsed lung, which is the likely reason they can develop in the egg but cant transition to breathing air and die at hatching.
Nick