Modern mammals have unique hearing abilities, able to sense a broad range of volumes and frequencies using middle-ear features, including our eardrums and a few small bones. A new study from paleontologists at the University of Chicago in the US has revealed these physical features began to emerge nearly 50 million years earlier than we thought. They found their evidence within a 250-million-year-old fossil of the mammal ancestor, Thrinaxodon liorhinus. Using computed tomography scans of the