Which Animal Has the Strongest Jaw?

The saltwater crocodile (Crocodylus porosus) holds the record for the strongest bite force ever directly measured in a living animal, at approximately 16,460 newtons (3,700 pounds-force). Researcher Gregory Erickson measured this from a 4.5-meter crocodile in 2012. For comparison, a human bite force is about 890 newtons, and a lion's is roughly 4,450 newtons. Among extinct animals, Tyrannosaurus rex is estimated to have had a bite force of about 35,000–57,000 newtons. Interestingly, while crocodilians have immensely powerful closing muscles, their jaw-opening muscles are so weak that a person can hold a crocodile's mouth shut with their bare hands.