A man named Heinrch K. Erben came up with this theory. It's not too proof providing, but does make sense. He was an active Dinosaur egg digger. Over the years he collected a heavy amount of certain species and found a very strange observation. He didn't mention what species of dinosaur it was that he made this assumption on, but regardless it was very interesting. He claimed that the oldest dated dino eggs had a very thick shell and up until the latest dated dino egg which was very thin. The eggs of the same species were getting thinner over millions of years. If this was true then that would mean that there is a high possibility that the chances of a baby dinosaur to develop,  hatch, and be immune would be rare. With minimal baby dinosaurs would mean starvation of predators in which would  change the whole environment. In the end based on this theory herbivores would increase and exhaust the food and  water area's, in which then comes the extinction.

Still this doesn't explain dinosaur "STRESS". So we know that the eggs got thinner but the real question you should be asking is WHY?. There's a simple enough answer for this. Certain animals, mammals, insects are known to not be able to handle the pressure of change. If you ever had a fish aquarium you'd know that if you buy a fish you can't just throw it in your aquarium because they have to get used to the different water from the bag its in (from the store) to your tank. The ph levels are different, temperature change, your other fish, different oxygen levels, and the different environment. All of these things will create stress for the fish and its important that it's carefully and gradually brought into that new aquarium. Some life forms do not have this problem. Humans are very efficient with this. In some area's of Mexico the heat out there is so hot that people sleep during the day and work at night. In Canada the winter is long and temperatures reach a low as -45C, but people are doing ok out there. So humans are not sensitive to change. It's been known for quiet some time that some species of modern day birds and lizards have had the same effect with thin eggs because of stress from a change in the environment. Back when dinosaurs roamed the earth there could have been a large change in the temperatures causing this stress to occur. If this change did actually happen then the estrogen in the dinosaurs would surely cause this thin egg theory.

There you have it in a nutshell, errrrr a eggshell, or lack of one.

This is a pretty good guess by Heinrch K. Erben, but unfortunately he never was able to back this with more solid proof. It hasn't been proven that he even had the eggs, they were never shown and no one else really has made any finding of eggs that got thinner with the same species. He was the only one who mentioned anything strange about dinosaur eggs to provide evidence of extinction.

Come on Heinrch K.  The least you could've said is which species of dinosaur you were basing this research on?