Why is it important to understand how skulls deal with stress generated from bite force
writes a guest post on his latest paper on bite force in reptiles
Among animals there is great variation in skull shape, and this is related to a variety of environmental factors such as diet and life style.
The shape of an animal鈥檚 skull is closely linked to its function: the skull supports soft tissue such as muscles and other connective tissue which allow movement and support.
Lizards, despite looking superficially similar on the outside have large variation in skull shape. We set out to show how the differences in skull shape are related to stresses distributed through the skull during biting.
Our work, published today in studies how soft tissue and bone interact during biting motion, and the bite force. Our paper, is the first to include the front part of the lizard braincase. It also includes the soft tissue joints between bones. This study takes us a step closer to understanding why skulls are the shape that they are.
We used the skull of the South American tegu lizard as our model species as it鈥檚 a very charismatic creature with a varied diet. structures and bone construction and analyse bite force.
The technology we used for this 鈥渨hole picture鈥 approach is the same engineering software used to design bridge and aeroplanes, as it is able to track the motion and strain on many complicated pieces.听 For the analyses, we developed听a computer model made up听of听many individual bones held together by flexible material - just like the real skull. The muscles were represented by contracting struts and based on detailed anatomical dissections.
To enable calculations the model was divided into a large number of very simple tetrahedrons (finite elements). Results comprised images of the skull colour coded according to strain as well as plots of strain along the length of the skull and braincase.
Our results were surprising - we found the flexible material between the individual bones doesn鈥檛 act like a 鈥渟tress absorber鈥 as previously thought;听instead it听increases overall strain but spreads it more evenly throughout the skull. This event strain is important for normal growth.
These results are also of interest to the field of human biomedicine despite differences in skull shape and species. 听Humans can experience premature fusion of听skull听bones, result in skull deformities, in infant children.
In lizards, the part of the skull听that听houses the front of the brain (the chondrocranium) is made from cartilage and听varies听among species as to its shape and听mineralisation. Our study 听finds that听this structure had little effect on skull function and contradicts听previous suggestions that it might serve as a vertical support structure.
In the future we hope to study the structure and loading of many more species of lizards including species from Australia which we鈥檝e been measuring bite force in wild populations.
He talks further on this topic in a video produced for Australia's Science Media Centre, scimex.org
听
The paper was by Dr Marc Jones and an international team from University College London, University of Aberdeen, and University of Hull. It was funded by the听UK听Biotechnology and Biological Sciences Research Council and听the听Australian Research Council.
Among animals there is great variation in skull shape, and this is related to a variety of environmental factors such as diet and life style.
The shape of an animal鈥檚 skull is closely linked to its function: the skull supports soft tissue such as muscles and other connective tissue which allow movement and support.
Lizards, despite looking superficially similar on the outside have large variation in skull shape. We set out to show how the differences in skull shape are related to stresses distributed through the skull during biting.
Our work, published today in studies how soft tissue and bone interact during biting motion, and the bite force. Our paper, is the first to include the front part of the lizard braincase. It also includes the soft tissue joints between bones. This study takes us a step closer to understanding why skulls are the shape that they are.
We used the skull of the South American tegu lizard as our model species as it鈥檚 a very charismatic creature with a varied diet. structures and bone construction and analyse bite force.
The technology we used for this 鈥渨hole picture鈥 approach is the same engineering software used to design bridge and aeroplanes, as it is able to track the motion and strain on many complicated pieces.听 For the analyses, we developed听a computer model made up听of听many individual bones held together by flexible material - just like the real skull. The muscles were represented by contracting struts and based on detailed anatomical dissections.
To enable calculations the model was divided into a large number of very simple tetrahedrons (finite elements). Results comprised images of the skull colour coded according to strain as well as plots of strain along the length of the skull and braincase.
Our results were surprising - we found the flexible material between the individual bones doesn鈥檛 act like a 鈥渟tress absorber鈥 as previously thought;听instead it听increases overall strain but spreads it more evenly throughout the skull. This event strain is important for normal growth.
These results are also of interest to the field of human biomedicine despite differences in skull shape and species. 听Humans can experience premature fusion of听skull听bones, result in skull deformities, in infant children.
In lizards, the part of the skull听that听houses the front of the brain (the chondrocranium) is made from cartilage and听varies听among species as to its shape and听mineralisation. Our study 听finds that听this structure had little effect on skull function and contradicts听previous suggestions that it might serve as a vertical support structure.
In the future we hope to study the structure and loading of many more species of lizards including species from Australia which we鈥檝e been measuring bite force in wild populations.
He talks further on this topic in a video produced for Australia's Science Media Centre, scimex.org
听
The paper was by Dr Marc Jones and an international team from University College London, University of Aberdeen, and University of Hull. It was funded by the听UK听Biotechnology and Biological Sciences Research Council and听the听Australian Research Council.
Newsletter & social media
Join us for a sensational mix of news, events and research at the Environment Institute. Find out about听new initiatives and听share with your friends what's happening.
听听听