Think of the word which best fits each gap. Use only one word in each gap

Buried off the coast 0)of Peru, scientists have discovered the fossils of an ancient predator. [ ] first, the creature was thought to be an elephant; however, it has now been identified as a giant whale! [ ] to its massive size, this whale is believed to be the largest creature to have [ ] roamed the sea. With teeth twice [ ] long as those of a dinosaur, this monstrous beast would have preyed upon animals which measured [ ] to 8 metres in length. It is even possible that it ate other whales [ ] dinner! Researchers are unsure of [ ] the creature became extinct, but some speculate [ ] changes in the environment forced it to adapt its eating habits. Over time, it gradually evolved [ ] a smaller animal, similar to the whales of today. In [ ], scientists believe that modern-day sperm whales probably descended [ ] this prehistoric beast. But fortunately, they are much friendlier [ ] their distant relatives!