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Re: Theropod bluff & hunting (was re Dilophosaurus Forelimb Bone Maladies

On Sat, Mar 5th, 2016 at 4:13 PM, Tim Williams <tijawi@gmail.com> wrote:

> Mike Habib <biologyinmotion@gmail.com> wrote:
> > Most sharks are also small game hunters. Even large adult great whites
> mostly hunt juvenile pinnipeds that can be consumed in a bite or two.
> Further to this, the great white shark has to use its jaws to
> immobilize the pinniped fairly quickly (within < 1 min) to have any
> success at all.  Otherwise, the young pinniped can struggle free and
> escape from the shark's jaws.

Even further to that; great white sharks have to wait until they reach full 
adulthood before risking 
biting down on something bony and larger than bite-sized with any degree of 
force. It takes years for 
a great white's cartilaginous jaws to mineralise enough to be able to stand the 
stresses involved. That 
would seem to make them poor analogues for large theropod dinosaurs.

Wroe, S., D. R. Huber, M. B. Lowry, C. R. McHenry, K. Moreno, P. D. Clausen, 
and T. L. Ferrara. 2008. 
3D computer analysis of white shark jaw mechanics: how hard can a great white 
bite? Journal of 
Zoology 276: 336?342

One thing that tips the hunting of large game in the favour of the predator is 
co-operative hunting. 
Orcas for instance are capable of killing just about anything that lives in the 
oceans by working 
together, whereas they would struggle with any sort of large prey if they acted 
alone. Likewise, lions 
would be unlikely to tackle something as dangerous as a cape buffalo without 
considerable backup 
from pride members. 

If any species of multi-tonne theropod could be shown definitively to have 
hunted in well-coordinated 
groups, then I wouldn't discount the occasional hunt of an adult sauropod 
entirely. If the risk could be 
moderated by co-operative hunting strategies, then the potential gain would 
have been substantial. 

If you were to sum the many minor risks involved in hunting lots of smaller 
prey for a multi-tonne 
biped that could injure itself simply by falling, you might also find that less 
frequent higher-risk hunts 
of much larger prey become more feasible from a risk management perspective.


Dann Pigdon
Spatial Data Analyst               Australian Dinosaurs
Melbourne, Australia