Iconic NZ reptile Tuatara spits on mammal chewing theory

Iconic NZ reptile Tuatara spits on mammal chewing theoryWashington, May 30 : The tuatara, an iconic New Zealand reptile, which chews its food in a way unlike any other animal on the planet, has challenged 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.



In the study, scientists describe the highly specialised jaws of the tuatara. When the reptile chews, the lower jaw closes between two rows of upper teeth.


"Some reptiles such as snakes are able to swallow their food whole but many others use repeated bites to break food down. The tuatara also slices up its food, much like a steak knife," Marc Jones, lead author from UCL Cell and Developmental Biology, said.


"Therefore the relationship between extensive food processing and high metabolism has perhaps been overstated," he said.


The tuatara provides an example in which specialisation of the feeding mechanism appears to allow a broader diet.



The team used a computer model developed at the University of Hull which provides a novel way of investigating the evolution and biodiversity of reptiles, allowing complex moving structures to be studied in 3D and from all angles.

"We developed this virtual model using software that is widely used in the analysis of complex engineering systems. It is the most detailed musculoskeletal model of a skull ever developed and demonstrates the huge potential of this type of computer modelling in biology," Neil Curtis, co-author of the study from the University of Hull's Department of Engineering, said.

"It allows us to investigate movements within skulls that would be impossible to monitor in a live animal without using harmful X-rays which is not an option for protected species like the tuatara," he add4ed.

The study has been published in The Anatomical Record. (ANI)