STL Science Center

STL Science Center

07 December 2013

Climbing and Slashing

Artist Unknown
For the past few years there has been some discussion here and there concerning the use of the extra large pes claws of Dromaeosaurids, particularly important to us of course, is the use of these claws by Deinonychus. The original idea for the large claw of Deinonychus is that it is used in disemboweling and killing prey items. In this illustration that claw is being used a strike against a hadrosaur's neck. Usually the strike is depicted as being directed toward the belly of the animal, but the neck would be just as vulnerable to attacks. This mode of use has been studied since the debate began not too long ago.

©John Sibbick
As this slightly older illustration of Deinonychus shows, one of the thoughts behind the the use of the claws was that it could be used to aid the gracile hands in grasping and holding prey. None of the animals in this illustration are using their pes claws for anything other than grappling with their prey item. In this manner of hunting they are using their hands and mouths to wear down the Iguanodontid that they are attacking. This manner of attacking is relevant to the second argument for use of the pes claw by Deinonychus.

Photo by Davide Meloni
One of the arguments for use of the claw has stretched the traditional boundaries of thought concerning the oversized foot claw of Deinonychus. In 2006 Manning et al fully explored the concept of Deinonychus claws as large climbing tools rather than as weapons of destruction and death. Climbing and grasping ability as well as the ability to use this claw as a weapon of disembowelment were tested using analyses of morphology and a robotic model by the researchers in question. All of the analysis done determined that climbing and grasping were far more likely uses of the claw than a disemboweling strike. The use of the claw in climbing could have serious implications in the generation and evolution of arboreal-terrestrial gliding flight and eventually powered flight.

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