Scientists have identified a new species of ancient porpoise with a chin length unprecedented among known mammals and suggest the animal used the tip of its face to probe the seabed for food.
Related to living crown porpoises, the extinct Californian porpoise, Semirostrum ceruttii, had an extension of its jaw called a symphysis — the analogue of the human chin — that measured 85 centimeters in the best-preserved specimen, researchers said. The typical symphysis of a crown porpoise measures one or two centimeters.