Xiphactinus was one of the most extreme fish of the Late Cretaceous, living around 100–66 million years ago. This giant predatory bony fish reached up to 6 meters (20 ft) in length and weighed around 400 kg (880 lbs). It ruled the Western Interior Seaway that once split North America in two. Fossils show Xiphactinus swallowed prey whole—including a 3-meter (10 ft) fish found preserved inside its stomach. That meal likely killed it, creating one of the most famous “last meal” fossils ever discove