This is a Sperm whale ear drum. The Sperm whale is the largest toothed predator on earth, growing between 52-67ft in length. Sadly, they are considered a vulnerable species, due to being hunted for their oil, which was used in lamps and candles. Sperm whale spit, or ambergris, is highly sought after and worth more than gold as it is a highly prized perfume ingredient. Their brain is the largest known of any animal, whether modern and extinct, and they use echolocation to understand their environment. They emit a series of clicks as part of this echolocation, which travel back along the lower jaw via a fat-filled canal, which transmits sound to the inner ear.