Check out this link. Its an amazing fossil of a marine reptile, Chaohusaurus, giving birth. Three babies can be seen, including one in the process of being born. What a story this picture tells; I wonder why the mother died during child birth? While that is a question that cannot be answered (at least by me); this fossil is an important link in our evolutionary record. Per the scientists in the article, this fossil demonstrates that live birthing sea creatures probably evolved from land based animals.