Monday, April 14, 2008

Modeling the Greatest Extent Varanid's Bite


The fearsome Komodo dragon is the world's largest living lizard and can take very large animal prey: now a new international study has revealed how it can be such an efficient killing machine despite having a wimpy bite and a featherweight skull.

A member of the goanna family with ancestors dating back more than 100 million years, the dragon (Varanus komodoensis) uses a combination of 60 razor-sharp serrated teeth, powerful neck muscles and what researchers are calling a "space-frame" skull to butcher prey with awesome efficiency, the study found.

They note that the dragon – inhabiting the central Indonesian islands of Komodo, Rinca, Flores, Gili Motang and Gili Dasami – shares the feeding and dental characteristics of extinct dinosaurs, sharks and sabre-toothed cats. Scientists Karen Moreno and Stephen Wroe from the University of New South Wales have used a computer-based technique called Finite Element Analysis (FEA) to test the bite force and feeding mechanics of the predator. Their findings are to be published in the latest issue of the Journal of Anatomy.

Normally used in the analysis of trains, planes and cars, the technique allowed the team to "reverse engineer" nature's design to assess the mechanical forces that a Komodo skull can handle. "The Komodo has a featherweight, space-frame skull and bites like a wimp," according to Wroe, "but a combination of very clever engineering, and wickedly sharp teeth, allow it to do serious damage to even buffalo-sized prey.

“The Komodo displays a unique hold and pull-feeding technique," says Dr Wroe. "Its delicate skull differs greatly from most living terrestrial large prey specialists, but it’s a precision instrument, beautifully optimised to make the most of its natural cranial and dental properties.

"Unlike most modern predators, Varanus komodoensis applies minimal input from the jaw muscles when killing and butchering prey. But it compensates using a series of actions controlled by its postcranial muscles. A particularly interesting feature of the skull's performance is that it reveals considerably lower overall stress when these additional forces driven by the neck are added to those of the jaw-closing muscles.

"This remarkable reduction in stress in response to additional force is facilitated partly by the shape of the bones, but also by the way bone of different strengths are arranged within the skull."


Keeping this in mind, people ought to try modeling the bite forces of theropods. Since they had some pretty light weight and funky skulls themselves, the same technique might be of use. If this hasn't been done already.

4 comments:

Zach said...

It's been done at least once for Allosaurus, several times for Tyrannosaurus, and once (I think) for Tarbosaurus. I would like to see bite-force studies for maniraptor theropods, though, and perhaps Nigersaurus (talk about a featherweight skull).

Will Baird said...

Same technique?

Zach said...

I'll have to check 'n' see, but I think the technique was similar if not the same.

Dicing with Dragons said...

Ooh. Does anyone have a PDF of the Varanid paper?