Humpback whales from Google Images
Science tells us that; Cetacean ancestors probably moved into water before changing their diet (and their teeth)
Ancient Australian indigenous culture tells us that whales were ancestors living on the land who moved back into the ocean; During the dreamtime period Gyian intermingled with other creatures, passing on the Laws of Baiyami. He later changed form from a bird of the land to live as he does today in the ocean as a whale. This was the birth of Gyian on Earth.