Hi, Jenna, I received your class' questions. Here is a summary of the answers to the questions they asked about whales and dolphins. I've only answered questions about marine mammals because I just didn't know the answers to some of the others and don't want to guess and pass on wrong information. You could probably find answers to most of them in an encyclopedia, though. I hope this helps you and your class, Cara The Greek word for dolphins is "delphis" and this today has become the English word dolphin. Manatees are the only marine mammals that are herbivorous and they share a common ancestor with elephants, one of their closest living relatives. Although this doesn't answer all of your questions, I hope it helps!