killed pregnant mother

Question
We found an iguana today who was hit by a car but still alive but suffering.  She passed.  She had an egg that dropped from her that we took in hopes of saving it.  I'm not sure if it's been fertilized but was hoping you might be able to offer some info as to how to care for it and how to tell if it is a live egg.  Thanks in advance.  It's sitting in a blanket warming from a lamp now so time is of the essence.

Answer
Hi Car, The critical things right now are to keep the egg from dehydrating, keep it from over-heating and to keep it in the same position (unlike bird eggs which are rotated). The temperature range you should aim for is 83 - 86 F. If the area under the lamp feels warm to your hand it is likely too hot for the egg. Iguanas bury their eggs to incubate them. In captivity the eggs are half buried in slightly damp vermiculite which can be purchased at garden stores. The incubation container is simply a plastic container about 3 - 4 inches deep which can hold a 2 inch depth of damp vermiculite. You can use clean potting soil in a pinch. Wet the media and squeeze out as much water with your hand as you can. The resulting consistency and dampness is what you need. Make an impression in the moist soil/vermiculite and set the egg in it, so that it is half buried. The egg will draw moisture from the media as needed.  Try to keep the egg in the same position when you move it. A lid with some small air holes can be put on the container. Iguana eggs can take anywhere from 70  to 120 days to hatch, you will likely need to re-moisten the media during that time. Infertile eggs usually start to discolour and collapse after a week or so of incubation while fertile eggs retain their shape and colour. After a couple weeks of incubation you should be able to see veins in a fertile egg by shining a flashlight through it.
This is very compassionate of you to try to do this, I wish you the best of luck with your egg!