The tuatara, an iconic New Zealand reptile, chews its food in a way unlike any other animal on the planet – challenging the widespread perception that complex chewing ability is closely linked to high metabolism.
Using a sophisticated computer model, scientists from UCL and the University of Hull demonstrate how the tuatara is able to slice its food like a “steak knife”. The tuatara’s complex chewing technique raises doubts about the supposed link between chewing and high metabolism in mammals.
The New Zealand tuatara (Sphenodon) is a lizard-like reptile that is the only survivor of a group that was globally widespread at the time of the dinosaurs. It lives on 35 islands scattered around the coast of New Zealand and was recently reintroduced to the mainland. Its diet consists of beetles, spiders, crickets, small lizards and, occasionally, sea birds.
In a paper published in The Anatomical Record, scientists describe the highly specialised jaws of the tuatara. When the reptile chews, the lower jaw closes between two rows of upper teeth. Once closed, the lower jaw slides forward a few millimeters to cut food between sharp edges on the teeth, sawing food apart.