Tuatara cuts up its food

Source: scientias.nl
Through its complex chewing action, the tuatara cuts up its food before eating it. Many other animals do this, of course - but they are all mammals. This is the first description of this technique in a reptile.
English scientists described this special tuatara (Sphenodon) chewing technique in the academic journal The Anatomical Record. The tuatara can slice apart its prey by moving its jaws. The lower jaw closes between two rows of upper teeth. With its prey between its jaws, the tuatara moves its lower jaw a few millimetres forward, literally sawing its prey in half. The chewing technique has been analysed using computer models, revealing that the two parts of the lower jaw are not fixed, but can move independently of each other. Until now, this kind of chewing method had only been seen in mammals. The assumption was that such a method was developed only by animals with rapid metabolisms and a need for large amounts of food. And yet the tuatara is a reptile. The sawing action of its jaws allows it to eat all kinds of prey, including beetles, spiders, crickets and small lizards. A tuatara was even discovered to have decapitated a marine bird.

The tuatara’s chewing technique shouldn’t necessarily come as such a surprise. Some dinosaur fossil remains indicate use of the same technique. Various anatomical characteristics of the tuatara also qualify it as a ‘living fossil’: these reptiles are still closely related to animals that lived in a distant past and became extinct long ago.