Mechanical implications of morphological
variation in the skulls of canids.

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Capturing and killing prey poses mechanical challenges for the skull, teeth and limbs.  Differences in prey type and hunting strategy have resulted in marked variation in skull morphology among carnivorous mammals.  Nowhere is this more apparent than within the dog family, Canidae, making it an ideal group within which to study the relationship between skull form and performance. Large mammal specialists, such as the African wild dog (Lycaon pictus) and bush dog (Speothos venaticus) have short broad skulls associated with large bite forces, while small mammal specialists, such as the Ethiopian wolf (Canis simensis) and maned wolf (Chrysocyon brachyurus) have long narrow skulls, that result in fast closing jaws. Generalist taxa, such as black-backed jackals (Canis mesomelas) have intermediate skull dimensions.

 

 

 

 

 

 

 

 

 

 

 

 

We expect that short broad jaws should be stronger under torsional loading than long narrow jaws. This should in turn place upper limits on the niche breadth of small mammal specialists.  Despite this prediction, some small mammal specialists are known to hunt large prey on occasion. Are such behaviors feasible for these taxa in the long term, or do they represent risk-prone behaviors at times of low resource availability? Understanding the mechanical performance capabilities of different skull morphologies provides one way of answering these questions.

We are studying taxa from two monophyletic canid lineages, the South American and Holoarctic canids.  Both lineages contain taxa that have independently evolved morphologies associated with prey specializations. Working with the Biomesh team, we are using finite element analysis to investigate mechanical performance under different loading patterns, designed to simulate different biting styles, including bilateral canine, unilateral canine and incisor biting.  Our results will help us to generally understand the role of skull morphology in prey killing and feeding, the role that different parts of the dentition play in prey apprehension, and limitations that different skull morphologies place on the type of prey that can be taken. 

Contact: Graham Slater