The tuatara, a New Zealand reptile, chews the food differently than it does any other animal on the planet. This challenges the widely accepted notion that a complex of chewing ability is closely related to rapid metabolism.
Using a sophisticated computer model, scientists from University College London and University of Hull, also in the UK, have shown how the tuatara is able to cut your food in a similar way as you would a steak knife.
The tuatara has a look similar to a lizard and is the only survivor of a group that at the time of the dinosaurs was distributed all over the world. The tuatara lives on 35 islands scattered around the coast of New Zealand, and was recently reintroduced in the main islands. Their diet consists of beetles, spiders, crickets, lizards and sometimes birds.
In research, the team of Marc Jones, Department of Biology at University College London, and Neil Curtis of Engineering Department at the University of Hull, described the highly specialized jaws tuatara. When the reptile chews, the jaw closes between two rows of upper teeth. Once closed, the lower jaw slides forward a few millimeters, cutting food between the sharp edges of the teeth.
As mammals are those with the most sophisticated form of chewing, this parameter has been associated by scientists with the rate of metabolism. A sophisticated system of chewing should therefore be unique to animals with fast metabolism. However, the tuatara chews their food so complex, while their metabolism is faster than other reptiles with simpler skills of oral food processing. Therefore, perhaps has been overestimating the relationship between the rate of metabolism and the capacity to process oral food.
Although currently chewing mechanism such as the tuatara be rare, there are fossils found in Europe and Mexico show that at the time of the dinosaurs some fossil relatives of the tuatara used a similar system and, therefore, this exotic form of chewing was much more common.