I found this egg when I was digging (with permission) by a tree in Glen Rose, TX which is by Dinosaur Valley State Park. It was a nesting site, I knew that because everything was covered with baby Dino Do-do which is what probably preserved it.
The eggs look like they were leathery. When they died, the sticky fluid leaked out and you will see things stuck to the egg. Some of the fluid that was still viable formed parts of creatures, some are strange, too. You can see all kind of tissue!
This egg seems to have a tiny long head near the cluster of back plates on top. The other Stego heads look like Sea Horses, with tiny plates on their little faces! It is 1.25″ x 1.85″ x .85″
You can see a tiny head in the upper left hand corner. It is 1/4″ long. There is a picture of an embryonic Stego head that looks just like it.
If you buy this egg, I will e-mail you copies of the three Scientific Articles I wrote about all the things I found!
This is a good picture of the tiny head.
You can see the similarities in these two heads.