Discovery of "Oldest Fully Aquatic Whale" Fossil Throws a Major Bone into Whale Evolution Story

In an article titled "Ancient whale jawbone found in Antarctica," the Associated Press reports that paleontologists have found "the oldest fully aquatic whale yet discovered," which is about 49 million years old. As we've discussed here on ENV in the past, whale evolution has faced problems because of the short timescale (~10 million years) allowed by the fossil record for whales to evolve from fully terrestrial mammals to fully aquatic whales. As Richard Sternberg has argued (see here, here ...