Sometimes it’s good to be a big baby. That’s what scientists are learning from a skeleton at the Natural History Museum of Los Angeles, in California. It belongs to a marine reptile known as Polycotylus (Pahl-ee-KOAT-eh-luss). Inside the fossil skeleton, scientists found the bones of a developing baby. By comparing that fossil to other young plesiosaurs, researchers are figuring out how these animals grew. Polycotylus is a type of plesiosaur (PLEES-ee-oh-sawr). These reptiles