Tuatara Reptile Can Slice Food Like a Steak Knife Say Researchers
Researchers from University College London (UCL) have found that the tuatara, a reptile found in New Zealand, chews its food in a way unlike any other animal on the planet. The tuatara is able to slice its food like a steak knife by sliding its jaw forward. The findings challenge the widespread theory that complex chewing ability is restricted to warm-blooded animals.
The tuatara's diet consists of beetles, spiders, crickets, small lizards and, occasionally, sea birds. In a paper published here in The Anatomical Record, scientists describe the highly specialized 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.
Lead author Dr. Marc Jones, UCL Cell and Developmental Biology, with colleagues from the University of Hull, developed a computer model to demonstrate how the tuatara is able to slice its food. The team reports that due to the shape of the jaw joint, as the jaws slide forwards they also rotate slightly about their long axes. This makes the shearing action more effective.
Dr. Jones says, "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. Because mammals show the most sophisticated form of chewing, chewing has been linked to high metabolism. However, the tuatara chews food in a relatively complex way but its metabolism is no higher than that of other reptiles with simpler oral food processing abilities. Therefore the relationship between extensive food processing and high metabolism has perhaps been overstated."