The oldest known whale to ply the Antarctic has been found, scientists say.

A 24-inch-long (60-centimeter-long) jawbone was recently discovered amid a rich deposit of fossils on the Antarctic Peninsula.

The creature, which may have reached lengths of up to 20 feet (6 meters), had a mouthful of teeth and likely feasted on giant penguins, sharks, and big bony fish, whose remains were also discovered with the jawbone.