First documented use of pharyngeal jaws to catch prey

The terrifying xenomorph creatures in the Alien, Alien vs Predator, and upcoming Prometheus movies are heavily armed with natural offensive and defensive mechanisms, including acidic blood and a second set of jaws. Known as pharyngeal jaws, these exist within the throats of around 30,000 species of fish on Earth. In September 2007 US scientists announced their discovery that the moray eel uses these in an aggressive manner. Whereas most species use their pharyngeal jaws to help with swallowing food, morays project theirs forward into their mouths in order to capture prey. This is the first such documented use of pharyngeal jaws discovered in nature.