I find the subject of raptors intriguing, but I do have a question. Since the raptors were bipedial and relatively lightly-built, their back legs would have been essential to their survival. Almost any injury to such important structures would have been rapidly fatal to a creature relying on pursuit speed and kicking power. And wouldn't kicking a large and angry herbivore that basically consists of thick skin over huge muscles, ribs, pelvic bones, scutes, shields and flailing limbs that would have made vital organs difficult targets risky? Aside from the likely humiliation of breaking a nail, they would have been at high risk for shattering a leg trying such tactics, and that would have made them losers in Darwin's evolutionary derby. Perhaps that is why they had all but vanished by the mid-Cretaceous, giving way to the smash-mouth hunting tactics of the Tyrannosaurs?

Is it more likely that Raptors mostly used their razor-like teeth on smaller prey. If they did use claws, it was probably the impressive armament on their forelimbs which would have been much easier to control and less risky to survival if injured? If so, would the sickle claws be used only as a display structure (like a rooster) or a weapon evolved mainly for defense like the large slashing claw on the cassowary? These birds are incredibly dangerous when trapped in close quarters although they are more likely to run away than take chances with their valuable legs in a battle. It makes sense to risk an incapacitating injury only if the alternative is being eaten. The fossil of the Velociraptor vs. Protoceratops seems to elude towards the raptors using these claws for defense. If this is the case, prehaps the raptors may not have been as deadly as they are commonly shown, though they would have been deadly enough. But I find the idea of 1-ton Utahraptors leaping onto a sauropod to dispatch it extremely risky for the raptors, despite the birth rate! Could there be any fossil evidence to show conclusively that the raptors used their claws for hunting (like we have conclusive evidence of Tyrannosaurs hunting)?
from Leonard, age 14, ?, ?, ?; July 28, 2001

TOM: It is unlikely that a dromaeosaur could rip open the belly of a plant eater with a single kick, for the reasons you say. It is more likely that they used a combination of attacks: biting, arm claws, and foot claws.