Summary: Bird eggs possess a mineralized eggshell with a soft underlying fibrous membrane. These dissimilar material layers successfully evolved a structural attachment to each other as a conserved avian reproduction strategy essential to avian embryonic development. growth. and hatching of the chick. https://www.diegojavierfares.com/great-save-NAHMIAS-Miracle-Academy-T-shirt-Mens-Apparel-special-save/