Featured Research

from universities, journals, and other organizations

Iconic New Zealand reptile shows chewing is not just for mammals

Date:
May 29, 2012
Source:
University College London
Summary:
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.

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.
Credit: © Undy / Fotolia

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.

Related Articles


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.

Lead author Dr Marc Jones, UCL Cell and Developmental Biology, said: "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."

The team report 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 and demonstrates that the left and right lower jaws are not fused together at the front as they are in humans.

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

Dr Jones said: "The slicing jaws of the tuatara allow it to eat a wide range of prey including beetles, spiders, crickets, and small lizards. There are also several grisly reports of sea birds being found decapitated following predation by tuatara."

"Although the tuatara-like chewing mechanism is rare today, fossils from Europe and Mexico show us that during the time of the dinosaurs (about 160 million years ago) some fossil relatives of the tuatara used a similar system and it was much more widespread."

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.

Co-author Dr Neil Curtis from the University of Hull's Department of Engineering said: "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.

"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."


Story Source:

The above story is based on materials provided by University College London. Note: Materials may be edited for content and length.


Journal Reference:

  1. Marc Jones, Paul O'Higgins, Michael Fagan, Susan Evans & Neil Curtis. Shearing mechanics and the influence of a flexible symphysis during oral food processing in Sphenodon (Lepidosauria: Rhynchocephalia). The Anatomical Record, 29 May, 2012

Cite This Page:

University College London. "Iconic New Zealand reptile shows chewing is not just for mammals." ScienceDaily. ScienceDaily, 29 May 2012. <www.sciencedaily.com/releases/2012/05/120529211721.htm>.
University College London. (2012, May 29). Iconic New Zealand reptile shows chewing is not just for mammals. ScienceDaily. Retrieved March 28, 2015 from www.sciencedaily.com/releases/2012/05/120529211721.htm
University College London. "Iconic New Zealand reptile shows chewing is not just for mammals." ScienceDaily. www.sciencedaily.com/releases/2012/05/120529211721.htm (accessed March 28, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, March 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Lioness Has Rare Five-Cub Litter

Raw: Lioness Has Rare Five-Cub Litter

AP (Mar. 27, 2015) — A lioness in Pakistan has given birth to five cubs, twice the usual size of a litter. Queen gave birth to two other cubs just nine months ago. (March 27) Video provided by AP
Powered by NewsLook.com
Jockey Motion Tracking Reveals Racing Prowess

Jockey Motion Tracking Reveals Racing Prowess

Reuters - Innovations Video Online (Mar. 26, 2015) — Using motion tracking technology, researchers from the Royal Veterinary College (RVC) are trying to establish an optimum horse riding style to train junior jockeys, as well as enhance safety, health and well-being of both racehorses and jockeys. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Bear Cubs Tumble for the Media

Bear Cubs Tumble for the Media

Reuters - Light News Video Online (Mar. 26, 2015) — Two Andean bear cubs are unveiled at the U.S. National Zoo in Washington, D.C. Alicia Powell reports. Video provided by Reuters
Powered by NewsLook.com
Botswana Talks to End Illegal Wildlife Trade

Botswana Talks to End Illegal Wildlife Trade

AFP (Mar. 25, 2015) — Experts are gathering in Botswana to try to end the illegal wildlife trade that is decimating populations of elephants, rhinos and other threatened species. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins