Little reported fact since GOM asteroid has copped the blame for loss of dinosaurs.
The shells of American dinosaur eggs became so progressively pathologically thickened, apparently due to genetic mutation caused by atomic radiation, that the baby dinosaurs could no longer break through. In France, the opposite occurred, also it seems due to genetic mutation through the effects from irradiation. The shells of Gallic dinosaur eggs became progressively pathologically thinner and more fragile, so much so in fact that the shells could not hold the baby dinosaurs or embryos. So shellfishes also revealed different shell texture from around that age.
So what was going onhere on earth back in those times? One has to wonder, advanced tech wars?